COURT FILE NO.: CV-16-0151-00 DATE: 2023-05-19

ONTARIO SUPERIOR COURT OF JUSTICE

B E T W E E N:

Carolyn Rose Jaroli V. Popescu, for the Plaintiff Plaintiff

• and -

Dorie-Anna C.C. Dueck M.B. Lerner and S. Lewis, for the Defendant Dorie-Anna C.C. Dueck Defendant

HEARD: November 14, 15, 16, 17, 18, 21, 22, 23, 2022, at Thunder Bay, Ontario Mr. Justice W. D. Newton

Trial Judgment

Index

Overview ……………………………………………………..……….1 The Evidence

1. Chronology ……………………………………………………….....2 The Plaintiff and her Children
2. Carolyn Jaroli……………………………………………..….…3-27
3. Leonard Jaroli – son ………………………………….....……..28-30
4. Kellie-Ann Kusserow – daughter ……………………..…...…..31-32 Mrs. Jaroli’s Treating Doctors
5. Dr. Matthew Holmes – general surgeon ………………..….…..33-36
6. Dr. Margaret Anthes – radiation oncologist ………………..….37-41
7. Dr. Jacqueline Edwards - Mrs. Jaroli’s family doctor…...….....42-46
8. Dr. Ayman Hassan – Mrs. Jaroli’s neurologist ………………...47-51
9. Dr. Peter Hindle – physiatrist ………………………………......52-55 The Plaintiff’s Expert
10. Dr. James Chiarotto …………………………………..….……56-76 The Defence Witnesses
11. Dr. Dorie-Anna Dueck ……………………………..….……..77-128
12. Dr. Karen Gelmon …………………………………..………129-151 Positions of the Parties
13. The Plaintiff …………………………………….………......152-156
14. The Defence …………………………………………….......157-163 The Law
15. Liability ………………………………………………….…164-167
16. Causation ………………………….………………….….….…..168 Analysis and Decision
17. Liability …………………………………….………….…...169-179
18. Causation ……………………………………………….......180-194 Conclusion ………………………..………………..……..…....195-196

Overview

[1] Carolyn Rose Jaroli sues Dorie-Anna Dueck, a medical oncologist, for negligence in recommending that Mrs. Jaroli’s breast cancer be treated with chemotherapy and with the cancer drug Taxol [1]. Mrs. Jaroli argues that, as a result of this treatment, she developed peripheral neuropathy [2] which has caused her to suffer pain and disability.

The Evidence

1. Chronology

[2] The salient occurrences were:

Jan 13, 2014 abnormal mammogram Mar 12, 2014 diagnosed with breast cancer Apr 4, 2014 right breast lumpectomy & sentinel lymph node biopsy – Dr. Holmes May 6, 2014 first appt at Cancer Centre - consult with Dr. Dueck and Dr. Anthes May 13, 2014 multidisciplinary treatment plan Jun 9, 2014 Oncotype Dx testing results received Jun 19, 2014 second consult with Dr. Dueck – Mrs. Jaroli agrees to chemotherapy Jul 4, 2014 consult with Dr. Dueck and 1st chemotherapy with AC [3] Jul 23, 2014 consult with Dr. Dueck and 2nd chemotherapy with AC Aug 13, 2014 consult with Dr. Dueck and 3rd chemotherapy with AC Sep 3, 2014 consult with Dr. Dueck - discuss Taxol and side effects Sep 5, 2014 4th chemotherapy with AC Sept 24, 2014 consult with Dr. Sicheri prior to 1st chemotherapy with Taxol Sept 26, 2014 first chemotherapy with Taxol Oct 17, 2014 consult with Dr. Dueck - Mrs. Jaroli refuses further chemotherapy Dec 4, 2014 first visit with GP, Dr. Edwards Dec 29, 2014 radiation therapy to breast – ends Feb 2, 2015 Feb 20, 2015 consult with Dr. Dueck prior to hormone therapy Mar 24, 2015 consult Dr. Dueck – hormone therapy prescribed Mar 4, 2020 consult with Dr. Hassan, neurologist Sept 14, 2020 EMG study with Dr. Hindle

The Plaintiff and her Children

2. Carolyn Jaroli

[3] The plaintiff, Mrs. Jaroli, is 82 years old. She retired at age 65 from a long career caring for disabled children at a group home. She is divorced and has two children, Leonard Jaroli and Kellie-Anne Kusserow. Both Leonard and Kellie-Anne reside in Thunder Bay and see their mother often. Another daughter, Anne-Marie, died from cancer at age 54, having first been diagnosed with Hodgkin’s lymphoma at age 21. Mrs. Jaroli’s mother was diagnosed with colon cancer at about age 80.

[4] Her current complaints that she attributes to what is alleged to be unnecessary treatment recommended by Dr. Dueck are of peripheral neuropathy, a burning sensation and weakness in her lower legs and feet.

[5] Prior to her cancer diagnosis, Mrs. Jaroli had a number of health problems. She was diagnosed with type 2 diabetes at about age 63 and has been prescribed metformin since then. She said that she had some “ tingling ” in her right leg which “ went away ”, never to return, after she lost about 30 pounds at that time. She has always struggled with her weight and describes herself as obese. In 2014, prior to her cancer treatment, she weighed about 295 pounds, on a five-foot, seven-inch frame. At that time, Mrs. Jaroli had complaints of swelling in her right lower leg and foot which “ felt funny ” but not painful. She had been a smoker for 48 years and quit in 2005. In 2007, she was diagnosed with colon cancer and had a polyp removed.

[6] In 2014, Mrs. Jaroli was diagnosed with breast cancer, following an abnormal mammogram discovered during routine screening in January. After an ultrasound and a biopsy in March, Mrs. Jaroli was referred to a surgeon, Dr. Holmes, to discuss treatment options. Rather than a mastectomy, Mrs. Jaroli elected to have a lumpectomy, followed by radiation. She testified that she told Dr. Holmes that she did not want chemotherapy.

[7] On April 4, 2014, Dr. Holmes performed the lumpectomy and excision/biopsy of the sentinel lymph node [4]. On her follow up consultation, Dr. Holmes told Mrs. Jaroli that the hospital had lost the lymph node and that there was no point in repeating the procedure. She testified that he told her that there was a 13 to 18 per cent chance that cancer would re-occur. Dr. Holmes referred her to the Cancer Centre at the Thunder Bay Health Sciences Centre on April 29, 2014.

[8] A week later, Mrs. Jaroli had her first appointment at the Cancer Centre. Mrs. Jaroli attended with her daughter, Anne-Marie. Mrs. Jaroli described her conversation with Dr. Dueck, a medical oncologist, as follows:

…and she came in, and just started talking right away about different - she, she talked about the treatment - I had chose radiation. She didn't mention chemo right away because my daughter spoke up and said, well, what about chemo, and Dr. Dueck said no, in her opinion, that would be over treating, and then I spoke up and I said, well, that's good because I do not want chemo.

And other than talking a little bit about the treatment, the radiation and then she said I could be on a pill for five years, and then that was it, and as we got up to leave, Dr. Dueck asked me if I would sign a release form so she could send my tumour to the States, and she said she would have the results back in about two weeks, and that's how we left our first appointment.

[9] As a result of that conversation with Dr. Dueck, Mrs. Jaroli thought she would be waiting to be called for radiation therapy.

[10] However, in cross-examination, Mrs. Jaroli testified that she did not remember that Dr. Dueck left the chemotherapy option for her to consider and believed that that conversation did not occur as she was adamant that she told Dr. Dueck that she did not want chemotherapy. When confronted with the following nursing note made the same day:

met with Dr Dueck today- she offered either Oncotype DX or would give patient chemo anyways if she wanted it since missing information from lymph node status

pt leaning toward having chemo

Mrs. Jaroli admitted that the conversation likely occurred but that she could not recall it.

[11] That same afternoon, Mrs. Jaroli met with Dr. Anthes, a radiation oncologist. Mrs. Jaroli testified that Dr. Anthes told her that she was not a “ good candidate for chemo ” to which Mrs. Jaroli replied, “ that’s good, because I don’t want chemo .”

[12] Several weeks passed as Ms. Jaroli waited to hear from the Cancer Centre about beginning radiation therapy. As she was anxious that cancer might be “ eating me up ”, she called the Cancer Centre and learned that Dr. Dueck was waiting for the report from the tumor. Mrs. Jaroli eventually had her second appointment with Dr. Dueck on June 19, 2014.

[13] Mrs. Jaroli attended with her daughter again. According to Mrs. Jaroli, Dr. Dueck began the consultation by immediately recommending chemotherapy. When asked by Anne-Marie why she was changing her opinion that “ chemo would be overtreating. Was it because of the test you sent away?”, Dr. Dueck replied that it was, and told Mrs. Jaroli she could have time to consider whether she wished to follow Dr. Dueck’s recommendation for chemotherapy. Because she was “ scared”, and because of the passage of time, Mrs. Jaroli agreed to follow Dr. Dueck’s recommendation for chemotherapy.

[14] On cross-examination, Mrs. Jaroli admitted that she might be mistaken in her recollection of what was discussed with Dr. Dueck at this second meeting.

[15] Tests were conducted to determine that Mrs. Jaroli was fit to begin chemotherapy. Dr. Dueck assessed Mrs. Jaroli on July 4, 2014, and, later that day, Mrs. Jaroli began chemotherapy. Chemotherapy continued every three weeks for four sessions.

[16] At the fourth treatment she met with Dr. Dueck who discussed the side effects of Taxol, the next drug to be used in chemotherapy. Mrs. Jaroli said that “ it didn’t sound good, that’s for sure. But I accepted it .”

[17] In cross-examination. Mrs. Jaroli was reminded that Dr. Dueck gave her a note outlining the side effects of Taxol. The note reads:

Taxol – side effects- low risk of allergic reaction x4 cycles during infusion -nail changes (loss, lifting or ridging) -muscle + joint pain (not permanent) -nerve damage in hands & feet (numbness & tingling) – can be permanent & painful.

[18] When confronted with Dr. Dueck’s consultation note that day in which Dr. Dueck states: “ She is at higher risk for the neuropathy, due to her history of type 2 diabetes.”, Mrs. Jaroli testified that she did not remember being told this.

[19] As she was leaving after her first treatment with Taxol she felt like her lips “ were growing ”, “ were thicker ”, and said that she “ couldn’t talk very well ”. “ That’s all I remember. It was different. I never felt that way with any of the other chemos .”

[20] She said that she was tired when she got home so she lay down and fell asleep. She woke up about 4:30 a.m. with pain in her whole body and felt that everything was “ on fire ”. She called the neighbour who delivered some Tylenol later that morning. By that point the pain was in her lower legs and feet.

[21] Because of pain she experienced after the treatment with Taxol she refused further chemotherapy.

[22] On her next scheduled visit with Dr. Dueck on October 17, 2014, she described her “ severe pain ” and refused further chemotherapy with Taxol. Pain medication was prescribed but Mrs. Jaroli declined medication for neuropathy according to Dr. Dueck’s chart notes. Mrs. Jaroli did not recall being offered any other medication and did not know what a neuropathic agent was.

[23] Over time, the pain has diminished. By early 2015 her leg pain and weakness had begun to improve. When she saw Dr. Dueck on February 20, 2015, Mrs. Jaroli agreed that she told Dr. Dueck that she did not have any neuropathy but that she had weakness in her legs and that Dr. Dueck told her to see her family doctor because arthritis was causing her leg problems. Mrs. Jaroli saw her family physician, Dr. Edwards on February 25, 2015, and discussed osteoarthritis but did not want to look into that then but would work on weight loss. When she saw Dr. Dueck on March 24, 2015, it was noted that she had a considerable amount of osteoarthritis.

[24] She describes the pain at present as “ band on both lower legs that burns all the time .” She said that her toes feel like they are “ made out of little blocks of wood .” She is also experiencing weakness. Various medications have been prescribed starting with Percocet and then Tramadol. Currently, she takes one pain pill, Tramacet, in the morning and one in the evening. She described her difficulties with mobility as worse at present, worse than in 2017.

[25] She also was experiencing pain in her knee which led to a knee replacement in 2018 on account of arthritis (end stage grade 4 osteoarthritis). She also had a hip replacement because of degenerative changes in 2020 which resolved the pain she was having with her hip. She said that the pain in her legs and feet continued, unchanged.

[26] She now uses a walker to ambulate and testified that she first acquired the walker about three weeks after the administration of Taxol. On March 12, 2015, she told Dr. Anthes that she “ continues to walk with a cane ,” and testified that she was switching between using a cane and a walker. She began using a cane at about age 62 and said that she used it as a “ walking stick ”, for security in wintertime.

[27] Her difficulty in ambulating restricts her activities. She relies upon her children to assist her with groceries and banking. She is not as active as she was prior to the cancer treatment.

3. Leonard Jaroli – son

[28] Mr. Jaroli moved back to Thunder Bay in 2007. Initially, he lived with his mother but does not any longer. He is married.

[29] Prior to his mother’s cancer diagnosis, he would spend time with her at least once a week. Together they would go to bingo or family gatherings. Often, they would go “ thrifting ’ meaning going to local thrift stores. He testified that, prior to her cancer diagnosis, his mother was able to get around on her own. That is no longer the case, and he assists her with anything that requires her to be outside her apartment.

[30] “ Thrifting ” is a rare occurrence, now only two or three times a year instead of weekly because walking is too difficult and painful.

4. Kellie-Ann Kusserow – daughter

[31] Like her brother, Ms. Kusserow went to bingo and “ thrifting ” with her mother pre-cancer. They also went to aquatics together.

[32] She described her mother as very independent prior to 2014 but since then she needs a walker and Ms. Kusserow assists with housework and does her mother’s laundry. She testified that her mother never complained of leg pain prior to receiving chemotherapy.

Mrs. Jaroli’s Treating Doctors

5. Dr. Matthew Holmes – general surgeon

[33] Mrs. Jaroli was referred to Dr. Holmes who performed a right breast lumpectomy and sentinel lymph node biopsy on April 4, 2014. A lumpectomy is a removal of a tumor or other lesion in the breast with a margin or rind of normal tissue around it. A sentinel lymph node biopsy is the removal of the lymph node that the involved tissues would normally drain to, to check and see if cancer cells have migrated to the lymph node. Sentinel, in this context, means the first lymph node or lymph nodes in the drainage pathway where the tumor might spread to. The sentinel lymph node is located through locally injected dye at the source of the tumor and also through radioactive tracing.

[34] Both the excised tumor and the excised sentinel lymph node were sent to pathology for analysis. At some point, between excision of the sentinel lymph node and the pathology department, the sentinel lymph node, tissue about 1 cm in diameter, was lost.

[35] On April 29, 2014, Dr. Holmes wrote a referral letter to the Cancer Centre stating:

Please see this woman regarding her margin negative – grade II 9 mm invasive ductal carcinoma (with ductal and lobular futures). Although we removed a blue sentinel lymph node with 10 second ex-vivo target count of just over 5000 following successful mapping, the pathologist did not find the specimen in the jar. Clearly this represents a difficult situation with respect to staging of her disease.… Overall, given her primary tumor factors, her overall risk of lymph node metastasis is in the range of 13 – 18 % based on MSK nomogram (ER status currently pending).… If she would be a candidate for chemotherapy, I think Oncotype testing should be considered and a decision will have to be made regarding whether or not to provide axillary radiation. I have fully disclosed all of this to Mrs. Jaroli over about 30 minutes of discussion today and I think she is well oriented to the issues and challenges….

[36] Dr. Holmes testified that not knowing whether the node was positive or negative for cancer places the medical oncologist in a very difficult situation. The nomogram is only an estimate of the cancer status of the lymph node.

6. Dr. Margaret Anthes – radiation oncologist

[37] Dr. Anthes was part of the treatment team at the Cancer Centre and supervised the treatment of Mrs. Jaroli with 25 treatments of adjuvant (preventative) breast radiation from December 29, 2014, to February 2, 2015.

[38] Dr. Anthes was also part of the multidisciplinary treatment team consisting of a surgeon, radiologist, pathologist, medical oncologist and radiation oncologist who discuss new cases and come up with a consensus treatment plan. Dr. Anthes recorded the consensus plan formulated on May 13, 2014 for Mrs. Jaroli. After recording what was known of Mrs. Jaroli’s cancer the treatment plan was:

Send for Oncotype – if low grade – AI + XRT – if high grade – consider chem

[39] Dr. Anthes testified that tumors are sent away for Oncotype testing which “ is like a 21 gene assay ” and is further information regarding the “ aggressiveness of the tumor, or the recurrence risk ”. With that information, a decision is made whether a patient would need chemotherapy in addition to the anti-estrogen therapy. If low grade, the treatment would be anti-estrogen therapy plus radiation. If high grade, then chemotherapy would be considered.

[40] Dr. Anthes testified that, in 2014, for patients who were intermediate grade, and known negative node, it was up to the physician and the patient to decide whether treatment would include chemotherapy.

[41] Mrs. Jaroli’s assertion that Dr. Anthes told her that she was not a good candidate for chemotherapy was not put to Dr. Anthes.

7. Dr. Jacqueline Edwards - Mrs. Jaroli’s family doctor

[42] Dr. Edwards has been Mrs. Jaroli’s family doctor since December 2014, after her chemotherapy had started and about two months after the single treatment with Taxol.

[43] The chart entry on this visit includes: “using a walker 2ndary to weakness from chemo, normally very active.” Questioning on this entry led to an exploration into whether Dr. Edwards was qualified to give expert opinion evidence on the effects of chemotherapy. After questioning on qualifications and submissions from counsel, I ruled that Dr. Edwards was not qualified to give expert opinion evidence on the effects of chemotherapy. Her evidence was that her only involvement with Taxol was looking up the side effects of Taxol after Mrs. Jaroli gave her history. As she did not know the cause of Mrs. Jaroli’s neuropathy, she referred Ms. Jaroli to Dr. Hassan, a neurologist in October 2019.

[44] Dr. Edwards testified that she sees Ms. Jaroli routinely a few times a year depending on Mrs. Jaroli’s health complaints. She is monitored regularly for diabetes, bloodwork, and blood pressure. She is on medication for those conditions and has had significant issues with arthritis causing pain which resulted in a knee replacement in 2018 and a hip replacement in 2020. She prescribes Tramacet to Mrs. Jaroli for pain.

[45] Dr. Edwards also testified that neuropathy is quite common for “ long-standing poorly managed diabetics .”

[46] Other conditions suffered by Mrs. Jaroli included shingles in 2015, arthritis in the joints as discussed, and congestive heart failure and chronic obstructive pulmonary disease.

8. Dr. Ayman Hassan – Mrs. Jaroli’s neurologist

[47] Dr. Hassan is a general neurologist in Thunder Bay who treats mostly stroke patients but also treats patients with epilepsy, peripheral neuropathy, other peripheral nervous system disorders and spinal cord disorders.

[48] He described peripheral neuropathy as arising from either a focal issue, secondary to stroke or injury, or a systemic issue. He saw Ms. Jaroli in March 2020 who was referred to him to assess her painful post–chemotherapy peripheral neuropathy and her post intention hand tremor. He testified that he did not have any supporting documentation for the diagnosis of post–chemotherapy peripheral neuropathy but was satisfied that Ms. Jaroli had peripheral neuropathy. He noted that she was diabetic which could account for the neuropathy. He diagnosed the hand tremor as a familial essential tremor attributable to her genetic history.

[49] He noted that Mrs. Jaroli reported that she has burning pain in feet and lower legs, more on the right than on the left. She described to him that she had the worst pain in the morning for 30 to 45 minutes after awakening. Burning pain is one of the typical symptoms of peripheral neuropathy.

[50] Dr. Hassan referred Mrs. Jaroli to Dr. Hindle for nerve conduction studies for further investigation of her symptoms.

[51] No questions were asked of Dr. Hassan regarding the specific cause of Mrs. Jaroli’s peripheral neuropathy.

9. Dr. Peter Hindle – physiatrist

[52] Dr. Hindle is specialist in physical medicine and rehabilitation currently specializing in electro diagnostics, which includes nerve conduction studies. He testified that Mrs. Jaroli was referred to him by Dr. Hassan to rule out peripheral neuropathy or polyneuropathy.

[53] When he met with Mrs. Jaroli, he was told by her that she had problems with her legs since 2014 which she thought might have begun when she was getting chemotherapy for breast therapy. He noted that she had bad osteoarthritis of her right hip which was causing her a lot of pain and a right total knee replacement that was still bothering her. She also complained of weakness in the legs, worse on the right than on the left, and Dr. Hindle surmised that that was not surprising because of her hip and knee problems on the right side.

[54] He conducted motor and sensory testing of the lower legs and feet. He found that she had peripheral neuropathy, sensory greater than motor, in both her lower legs and feet. The burning pain that she described was consistent with a sensory neuropathy and he indicated that sensory nerves are very sensitive to trauma or diseases like diabetes. His report concluded:

Mild motor and moderate sensory neuropathy of the lower legs and feet that is likely secondary to diabetes and/or related to the chemotherapy medications back in 2013.

[55] In cross-examination, Dr. Hindle confirmed that he could not determine, one way or the other, what was causing Mrs. Jaroli’s neuropathy. He testified that most diabetics do develop some degree of peripheral neuropathy the longer that the disease goes on. He confirmed that he did not say in his report that chemotherapy was the significant cause of Mrs. Jaroli’s neuropathy.

The Plaintiff’s Expert

10. Dr. James Chiarotto

[56] Dr. Chiarotto is a medical oncologist who was tendered to give expert opinion evidence on the standard of care of a medical oncologist with respect to the prescription of chemotherapy to a patient with a breast cancer diagnosis in 2014 and on the cause of Mrs. Jaroli’s peripheral neuropathy.

[57] Dr. Chiarotto is a full-time medical oncologist at the Scarborough Health Network in Toronto and has had a full-time clinical practice for about 25 years. He has treated all malignancies and, more recently, has treated just solid tumors like breast, lung, and prostate cancers. Most recently, he is treating breast cancer, colon cancer, and lung cancer.

[58] He described the side effects of Taxol which can include nerve damage and peripheral neuropathy which may manifest as numbness or tingling in the fingers and toes.

[59] His expertise was not challenged with respect to the standard of care but was challenged as to his expertise in the cause of peripheral neuropathy. I ruled that Dr. Chiarotto was qualified to give an opinion on the cause of the plaintiff’s peripheral neuropathy in light of his experience with Taxol and his qualifications as an internal medicine specialist.

[60] Dr. Chiarotto reviewed the clinical notes and records with respect to Mrs. Jaroli’s cancer diagnosis and treatment and her general medical records.

[61] His opinion was that the chemotherapy chosen for Mrs. Jaroli was inappropriate, and that it was highly likely that the use of Taxol caused Mrs. Jaroli’s peripheral neuropathy.

[62] He described the choice of treatment as “ far too aggressive for this scenario ” given Mrs. Jaroli’s age and multiple medical comorbidities. He did not challenge Dr. Dueck’s findings and observations, only her conclusion to recommend chemotherapy which, in his opinion, was not warranted in the circumstances.

[63] He acknowledged that the absence of the sentinel lymph node made this a challenging situation for the medical oncologist as there was no way of determining whether the lymph node was positive or negative for cancer. He described the Oncotype Dx test that Dr. Dueck elected to use as a test used by medical oncologists to inform their decisions as to whether or not to give chemotherapy to their patients in order to reduce the risk of recurrence of the breast cancer. The recurrence score was 20 which did not identify high risk of disease, “ much closer to the low risk than it is to the high risk .” He said that this “ gives you some sense of confidence that this is not one of the higher risk cancers or one of the more dangerous cancers or one that you need to use chemotherapy to help prevent the cancer from returning .” In 2014, the Oncotype DX test was used to “ identify women with chemotherapy – sensitive cancer that would benefit, namely that they would live longer and have a lower risk of a cancer returning with chemotherapy .”

[64] In Dr. Dueck’s report of June 19, 2014, following receipt of the results of the Oncotype DX testing, Dr. Dueck stated the results confirmed “ a higher risk of systemic recurrence than initially considered .” Dr. Dueck stated that a reoccurrence score of 20, translating into a systemic risk over the next 10 years of 13%, placed Mrs. Jaroli in the Intermediate Risk Group. She concluded: “ I suspect that on this basis, the sentinel lymph node was likely involved with metastatic disease .”

[65] Dr. Chiarotto disagreed with the statement that the sentinel lymph node was likely involved because the Oncotype Dx score was not validated to give that kind of information.

[66] It was his opinion, that in 2014, the accepted clinical knowledge was that chemotherapy may be beneficial to patients with an Oncotype score of 25 to 31 and above, but not with a score of 20 “since 20 was very close to 18, which is at the upper limit of low risk.” This was contrary to the opinion of the defence expert, Dr. Gelmon, who had stated that, in 2014, the benefit of chemotherapy was unknown for patients with an intermediate Oncotype score, like Mrs. Jaroli [5].

[67] It was his opinion that this score would not have merited what he described as a “ very aggressive ” chemotherapy regime for a patient at age 72 with multiple comorbidities. He referred to certain studies to support his opinion.

[68] Her comorbidities, age, obesity, diabetes, and positive PR (progesterone) status predisposed Mrs. Jaroli, in his opinion, to develop nerve damage, a known complication of Taxol.

[69] In cross-examination, Dr. Chiarotto acknowledged the treatment dilemma: that overtreatment could lead to permanent side effects and undertreatment, to death.

[70] He acknowledged that the sentinel lymph node provided the most established and reliable information to obtain an accurate prognosis with respect to the risk of cancer recurring. He described this as “ essential ” information and that the lost node presented a “ challenging ” and “ unusual ” situation for Dr. Dueck since there is no way of knowing for certain whether the cancer cells have migrated away from the primary tumor.

[71] Dr. Chiarotto testified that other factors could provide some clues on the likelihood that the missing node was positive. Based on the size of the tumor, 9 mm, he estimated that there was a 16% chance that the lost node was positive. Dr. Dueck had initially estimated that there was a 10% chance that the node was positive while Dr. Dueck’s expert, Dr. Gelmon estimated the chance the node was positive as approximately 20%. Based on these estimates, he agreed that there was somewhere between a 1 in 5 and 1 in 10 chance that Ms. Jaroli’s cancer had spread.

[72] The Cancer Care Ontario guidelines for 2014 [6] were reviewed with Dr. Chiarotto. He agreed that patients with positive nodal disease in early breast cancer would merit chemotherapy, that is, “ a positive node was an indication for chemotherapy in 2014 ”.

[73] Cancer Care Ontario also considered the role of Oncotype Dx testing in determining whether chemotherapy was appropriate in node negative or node positive with micro metastases. However, because the node was lost, Mrs. Jaroli node status was unknown. Cancer Care Ontario stated:

The additional benefit of chemotherapy varies by RS [reoccurrence score], whereby low scores have little to no benefit, and high scores have the most benefit. The utility of chemotherapy in the intermediate RS zone is less clear at this juncture, although a phase III clinical trial ( TAILORx ) may help address this once reported.

[74] Dr. Chiarotto agreed with this statement from Cancer Care Ontario, that the benefit of chemotherapy for cancer patients with a negative node and intermediate score was unknown in 2014, and not known until November 2018. Notwithstanding this statement from Cancer Care Ontario, Dr. Chiarotto testified that, in 2014, chemotherapy would not be offered to node negative patients with a recurrence score of less than 25.

[75] With respect to the role of the chemotherapy in the cause of Mrs. Jaroli’s peripheral neuropathy, Dr. Chiarotto had concluded that that Dr. Hindle had stated “ that chemotherapy had the significant role in causing the ongoing nerve damage ” in coming to his conclusion on causation. When confronted with Dr. Hindle’s actual evidence that he could not determine what was causing Mrs. Jaroli’s neuropathy, Dr. Chiarotto testified that his conclusions were based on his interpretation of Dr. Hindle’s report.

[76] In concluding his testimony Dr. Chiarotto repeated that he did not agree that the recommendation by Dr. Dueck was a reasonable exercise of clinical judgment in this case with a missing lymph node. The opinion of Dr. Gelman, the expert retained by Dr. Dueck, that Dr. Dueck met the standard of care in 2014 was also put to Dr. Chiarotto. The cross-examination of Dr. Chiarotto ended with this series of questions:

Q. I want you to assume, Dr. Chiarotto, that Dr. Gelmon will testify that Dr. Dueck met the standard of care in 2014, okay? I want you to assume that.

A. Yes.

Q. Okay. If she does that, would you agree that we then have a simple case of two expert physicians, you and her, looking at the management of a difficult cancer patient and disagreeing about the appropriate manner for treating the patient?

A. Yes.

Q. And, disagreeing about a question of clinical judgement?

A. Yes.

The Defence Witnesses

11. Dr. Dorie-Anna Dueck

[77] Dr. Dueck’s CV was filed as an exhibit and her academic and professional background was reviewed.

[78] Dr. Dueck is a medical oncologist. Medical oncology is a subspecialty of medicine that treats cancer patients with drug treatment. The drug treatment includes chemotherapy, immunotherapy and other drug treatments such as anti-estrogen therapy. She is and was, at the time of her treatment of Mrs. Jaroli, an academic medical oncologist which means that she is affiliated with a university teaching hospital.

[79] She obtained her medical degree from the University of Manitoba in 1997, completed her residency training in internal medicine in 2000 in Manitoba, and completed her medical oncology residency at the Ottawa Regional Cancer Centre in 2003.

[80] From 2003 to 2016 she was a medical oncologist at the Northwestern Ontario Regional Cancer Program in Thunder Bay responsible for treating all types of solid tumors. About 25% of her practice involved treating patients with breast cancer. Of those, approximately 90% required chemotherapy.

[81] From 2016 to present she has been a medical oncologist at the Saskatoon Cancer Centre. From 2021 to present, she has been the Program Director, Medical Oncology Residency Training program at the University of Saskatchewan.

[82] She sees about 375 new patients each year and estimates that she has treated approximately 8000 patients.

[83] While a medical oncologist in Ontario she conducted practice assessments on behalf of the College of Physicians and Surgeons of Ontario to ensure that physicians were meeting their competencies in medical oncology. From 2016 to present she has been on the Discipline Committee for the College of Physicians and Surgeons of Saskatchewan.

[84] Dr. Dueck was among the cancer physicians in Ontario who prepared the Cancer Care Ontario guidelines from 2014, although she was not present at the consensus meeting because of personal medical issues.

[85] Dr. Dueck’s testimony began with a general discussion about cancer. She said that cancer occurs when the normal cells in the body start to accumulate genetic mutations which grow uncontrollably and eventually develop into a tumor mass or lump. When the cancer spreads through the body it is Stage 4 cancer or metastatic disease which is incurable.

[86] To prevent the spread of cancer, the cancer has to be found early enough. When found early enough the surgeon can resect the cancer and then administer additional therapy (also called adjuvant therapy) to reduce the risk of the cancer coming back.

[87] Breast cancer is where cancer develops within breast tissue. There are two main types: ductal carcinoma and lobular carcinoma. Ductal carcinoma is when the normal cells of the breast duct mutate and lobular carcinoma occurs when the normal cells in the breast lobules mutate. Lobular carcinoma tends to spread to a non-sentinel lymph node. Ductal carcinoma is more likely to spread to a sentinel lymph node. Mrs. Jaroli had mixed ductal and lobular carcinoma of the breast.

[88] To determine prognosis of cancer the different pathological features of the cancer are examined. These include the size of the tumor, the grade of the tumor, the presence of lymphovascular invasion, hormone sensitivity, and node status.

[89] Size is based on the size of the cancer underneath the microscope. Grade refers to what the cancer cell looks like in relation to normal cells, with grade 1 looking normal and grade 3 looking very abnormal. Lymphovascular invasion means that the individual cancer cells have entered the tiny blood vessels and tiny lymphatic channels. Hormone receptor status tells the oncologist whether the cancer cells are estrogen, progesterone and, HER2 [7] receptive. Positive hormone receptivity means that the hormone acts as fuel for the cancer, making it grow and divide. Estrogen receptor positive is a good prognosis because the cancer can be treated with anti-estrogen therapy.

[90] As Dr. Dueck described, sentinel lymph node status is a “ really critical ” piece of information that tells the oncologist if the cancer has started to spread or not. If the sentinel lymph node is involved there is a higher chance of the cancer spreading. If the lymph node is negative, there is a lower chance of the cancer spreading.

[91] Other testing, such as the Oncotype Dx test, can assist in determining prognosis.

[92] Of the factors, Dr. Dueck testified that that the lymph node is the most important factor to tell the oncologist what the risk of recurrence is.

[93] Dr. Dueck testified generally about treatment for breast cancer. Once the cancer is discovered there are two surgical options: lumpectomy and mastectomy. Following surgery, adjuvant treatments begin. The choice of surgery has no bearing on whether chemotherapy will be indicated. If the patient has a mastectomy, then radiation is not required.

[94] Chemotherapy is the administration of anti-cancer medication by pill or intravenously. Mrs. Jaroli received chemotherapy intravenously.

[95] Radiation treatment involves a focal beam of ionizing radiation directed towards where the cancer started to kill any residual cancer cells that the surgery may not have been able to remove.

[96] Anti-estrogen treatment is a way to stop the cancer from dividing by stopping production of estrogen so that cancer is not exposed to that fuel if the cancer is estrogen receptor positive.

[97] If a patient is going to receive all three types of treatment, then chemotherapy is first, followed by radiation, followed by 5 to 10 years of anti-estrogen treatment.

[98] Whether chemotherapy is recommended depends on the probability of the cancer coming back. If there is a low chance that the cancer will return, then the oncologist may choose only radiation and antiestrogen treatment.

[99] Dr. Dueck testified that not having the sentinel lymph node meant that they were missing a critical piece of information needed to determine the stage and the risk of recurrence. She has never treated a patient where the lymph node had been lost other than Mrs. Jaroli.

[100] Dr. Dueck first met with Mrs. Jaroli on March 6, 2014, and Dr. Dueck’s two and one half page consultation note prepared following that meeting was reviewed. Dr. Dueck recorded the features of Mrs. Jaroli’s cancer: mixed cancer with lobular and ductal features, 9 mm single focus of breast cancer with clear margins, no evidence of lymphovascular invasion, estrogen and progesterone receptor positive and HER-2 negative, and grade 2 malignancy.

[101] Mrs. Jaroli’s comorbidities were reviewed, and it was noted that Mrs. Jaroli had no known complications from her diabetes. Past medical history is relevant in terms of whether the patient can tolerate chemotherapy and whether the patient’s life expectancy otherwise warrants chemotherapy. In this case, Dr. Dueck concluded that Mrs. Jaroli had a life expectancy of at least 10 years and that her other medical problems were well-controlled.

[102] Based on the known pathological features of the tumor, and in the absence of the sentinel lymph node, Dr. Dueck concluded that there was a 10% possibility that the cancer had spread to the sentinel lymph node. Had the sentinel lymph node been positive for cancer that meant that there was a high risk of the cancer returning and, therefore, Mrs. Jaroli would need chemotherapy. If the sentinel lymph node was negative then Dr. Dueck would do Oncotype Dx testing which would tell her if Mrs. Jaroli was low risk, needing anti-estrogen therapy or high risk, needing chemotherapy also.

[103] Mrs. Jaroli agreed with the recommendation that Oncotpye Dx testing should be done. Dr. Dueck testified that the Oncotype Dx testing does not replace knowing that the lymph node is positive or negative, but it gives some more information about risk.

[104] Side effects of chemotherapy were discussed including neuropathy. Dr. Dueck was to see Mrs. Jaroli once the Oncotype Dx testing results were known.

[105] The next stage in Mrs. Jaroli’s treatment was the discussion of her case at the multidisciplinary rounds. These conferences take place weekly and are a requirement of Cancer Care Ontario. The physicians on the team review the cases as a group. On May 13, 2014, the team met and agreed that the Oncotype Dx testing was appropriate. The group concluded that if the testing results were “ low grade ” then Mrs. Jaroli should receive anti-estrogen and radiation and, if “ high grade ”, chemotherapy should be considered. Dr. Dueck testified that there was no mention of an intermediate grade because the group did not think that Mrs. Jaroli was going to have an intermediate risk score.

[106] The Oncotype Dx recurrence score was 20 or intermediate risk. Scores between 18 and 31 were considered intermediate. This score translates into a 13% chance of the cancer recurring over the next 10 years when treated with anti-estrogen therapy alone.

[107] Dr. Dueck testified that the 13% risk of recurrence was a higher risk than she expected based on the tumor’s pathology. She also testified that the Oncotype Dx findings were only applicable to node negative cancer. The “ best case ” scenario was that Mrs. Jaroli had a 13% recurrence risk, but the risk could be higher because the status of the lymph node was not known. Based on the prediction graphs generated on the Oncotype Dx testing, chemotherapy plus anti-estrogen therapy could reduce the risk of cancer recurrence from 13% to about 5% in the best case scenario.

[108] Protocols for chemotherapy in early-stage breast cancer are recommended in the Cancer Care Ontario guidelines. All recommended therapy included taxane (Taxol) based chemotherapy protocols. The protocols available at the Thunder Bay Regional Cancer Centre were AC x 4 followed by T x 4, dose dense ACP and CMF. Dr. Dueck testified that dose dense chemotherapy is a much harder treatment to tolerate and is reserved for younger women who do not have any other medical problems. She described CMF as less effective but an option for a patient for whom anthracycline and taxane were contraindicated, such as someone with severe neuropathy or cardiac issues.

[109] Dr. Dueck’s next appointment with Mrs. Jaroli was on June 19, 2014. Dr. Dueck testified that, based on a review of her records, the appointment lasted about 50 minutes. The consultation note relating to this visit is just over one page in length. She discussed with Mrs. Jaroli that the recurrence rate was higher than initially considered and on the basis of that, Dr. Dueck suspected that the sentinel lymph node was likely involved with metastatic disease.

[110] At that time the risks or side effects of chemotherapy with Taxol were discussed and Dr. Dueck gave Mrs. Jaroli a handwritten note in which she outlined the side effects of Taxol. The note stated, “ low risk of allergic reaction ”. Side effects included “ muscle + joint pain (not permanent)” and “ nerve damage in hands & feet (numbness & tingling) – can be permanent & painful .” As Dr. Dueck stated in her consultation note, she told Mrs. Jaroli that she had a higher risk for neuropathy due to her history of type 2 diabetes.

[111] Based on their discussions, Mrs. Jaroli elected to proceed with chemotherapy. Dr. Dueck was asked if she told Mrs. Jaroli that chemotherapy would be “ over treatment ”. Dr. Dueck answered that she did not say this because, since she did not have the sentinel lymph node information, she did not know if chemotherapy was over treatment.

[112] Chemotherapy was delayed so that other tests can be conducted to ensure that Mrs. Jaroli was fit to begin chemotherapy. Dr. Dueck saw her patient before each dose of chemotherapy. She testified that Mrs. Jaroli had handled the first stage of chemotherapy “ beautifully ” as her therapy did not need to be delayed because she was not doing well.

[113] On the last dose of chemotherapy before beginning Taxol (September 3, 2014), Dr. Dueck reviewed the risks of Taxol again with Mrs. Jaroli. Dr. Dueck recorded the following in her consultation note:

There is also a risk of permanent painful sensory peripheral neuropathy that may interfere with fine motor activity. This may also include difficulty feeling the floor when she walks. As she has a history of type 2 diabetes and has in the past experienced diabetic neuropathy, she is at a higher risk for this development. She is accepting of the risk .

[114] On October 17, 2014, Dr. Dueck met with Mrs. Jaroli before her second chemotherapy with Taxol. At that time, Mrs. Jaroli declined further chemotherapy. Mrs. Jaroli told Dr. Dueck that she developed bad muscle aches and pain and had become bedridden. Dr. Dueck testified that the symptoms were consistent with sensory peripheral neuropathy. She renewed Mrs. Jaroli’s prescription for the pain medication, Tramadol. Dr. Dueck also offered Mrs. Jaroli a drug to help with the neuropathy but Mrs. Jaroli declined that medication.

[115] Dr. Dueck next saw Mrs. Jaroli on February 20, 2015, just after Mrs. Jaroli had finished radiation therapy, to discuss anti-estrogen therapy. Dr. Dueck noted that Mrs. Jaroli was experiencing generalized leg weakness that Mrs. Jaroli attributed to Taxol. Dr. Dueck’s recorded this in her notes:

However, this treatment was discontinued about five months ago. She does not have any residual neuropathy. I suspect that the generalized leg weakness in her legs is not attributable to her chemotherapy, but rather to possible arthritis as well as to gross obesity.

[116] Dr. Dueck testified that the side effects of Taxol are very predictable with muscle aches and neuropathy occurring after the first cycle which resolves prior to the second cycle.

[117] On follow-up with Mrs. Jaroli on March 24, 2015, to review the various tests necessary before beginning anti-estrogen therapy, Dr. Dueck noted that Mrs. Jaroli had advanced osteoarthritis. Mrs. Jaroli cancelled subsequent appointments with Dr. Dueck.

[118] Dr. Dueck concluded her examination in chief by testifying that she would not have done anything differently in her treatment of Mrs. Jaroli because the consequence of not treating with chemotherapy was death in circumstances where there was a possible benefit of chemotherapy.

[119] In cross-examination, Dr. Dueck repeated her testimony that she did not tell Mrs. Jaroli that chemotherapy was “ overtreatment ”. She confirmed that, on May 6, 2014, Mrs. Jaroli was not 100% certain that she wanted chemotherapy, but chemotherapy was something Mrs. Jaroli was considering.

[120] Dr. Dueck confirmed that not having the status of the lymph node made the treatment decision “ very difficult ”. She said that if Mrs. Jaroli’s lymph node was known to be negative she would still require the Oncotype Dx testing.

[121] The purpose of the Oncotype Dx testing was to determine the best case scenario for Mrs. Jaroli compared to the worst-case scenario. The worst-case scenario was that her lymph node was positive, and she needed chemotherapy. The best case scenario was that Mrs. Jaroli had a negative lymph node and an intermediate risk of her cancer returning. According to Dr. Dueck, in 2014, that meant that Mrs. Jaroli could have benefited from chemotherapy or not benefited from chemotherapy.

[122] The Oncotype Dx findings were applicable to women who had stage I or stage II node negative, estrogen receptor positive breast cancer who will be treated with five years of Tamoxifen, so it was unknown whether the findings applied to Mrs. Jaroli because her node status was unknown.

[123] Oncotype Dx testing gave Dr. Dueck information about the “ biological aggressiveness ” or the biological behaviour of Mrs. Jaroli’s specific disease rather than the “ pathological population – based data .” She described the Oncotype Dx testing as superior to the pathological features in understanding the risk. The test result could not tell Dr. Dueck whether the sentinel lymph node was negative or positive. She clarified her statement in her consultation note of June 19, 2014 in which she stated that the sentinel lymph node was likely involved as a misstatement in that she meant that the cancer had likely spread, not necessarily to the lymph node. There was a 13% chance of the cancer still being somewhere in Mrs. Jaroli.

[124] The decision to recommend chemotherapy was on the basis of two factors: that she was intermediate risk and may benefit from chemotherapy and that she may have a positive lymph node and would benefit from chemotherapy.

[125] Chemotherapy with Taxol is, according to Dr. Dueck, the most important part of the chemotherapy. She testified that “ if a woman needs to have chemotherapy to reduce her risk of recurrence, Taxol needs to be in that protocol .”

[126] Other chemotherapy regimens were available. CMF chemotherapy was for patients who could not tolerate standard chemotherapy but had low efficacy. Chemotherapy without Taxol was possible but would involve extra doses of the other medication which is known to reduce cardiac function.

[127] Dr. Dueck acknowledged, as she said in her consultation notes, that patients with diabetes have a higher risk of developing peripheral neuropathy after receiving treatment with Taxol and that there was no evidence of Mrs. Jaroli having peripheral neuropathy prior to the treatment with Taxol.

[128] Dr. Dueck had “absolutely no doubt” that what Mrs. Jaroli experienced “ with her severe pain and her muscle aches and heard joint achiness…. was from Taxol, absolutely .” However, she testified that, based on the cancer literature, it is very rare to develop permanent neuropathy after one cycle of Taxol.

12. Dr. Karen Gelmon

[129] Counsel for Dr. Dueck tendered Dr. Gelmon as an expert in medical oncology in the treatment of breast cancer in 2014. The scope of her proposed testimony was whether Dr. Dueck’s care of Mrs. Jaroli met the standard of practice for a medical oncologist in 2014 in Canada and, whether, on a balance of probabilities, Mrs. Jaroli’s sensory neuropathy was caused by Taxol.

[130] Dr. Gelmon graduated from medical school in 1979, completed her residency in internal medicine in 1983 and was certified as a medical oncologist in 1986. She has been involved in treatment, research, and education throughout her career. She has been an academic medical oncologist with British Columbia Cancer since 1990. She has a number of awards including election to the Canadian Academy of Health Sciences.

[131] She estimates that she sees approximately 250 patients per year in her career and that the vast majority of these patients have been breast cancer patients. She has authored or co-authored over 350 peer-reviewed journal articles, 80% of which were focused on breast cancer. She has prepared expert reports for litigation for both plaintiffs and defendants.

[132] Counsel for Mrs. Jaroli did not challenge Dr. Gelmon’s expertise in the treatment of breast cancer.

[133] Dr. Gelmon reviewed Mrs. Jaroli’s medical records, discovery transcripts of both parties, and Dr. Chiarotto’s expert report. Based on her review of the records, it was Dr. Gelmon’s opinion that Dr. Dueck met the standard of a care of a medical oncologist in 2014. With respect to whether Mrs. Jaroli’s peripheral neuropathy was caused by Taxol she deferred to the other experts who determined that the cause was “ multifactorial with a number of factors, including diabetes, as well as chemotherapy exposure and other factors as the cause .”

[134] The appropriateness of various therapies was discussed. Dr. Gelmon testified that chemotherapy was not appropriate in tumors where there is an extremely low risk of the cancer returning, “ 5% or something really small .” Chemotherapy was also not appropriate for someone who had a very short estimate of survival.

[135] Based on Mrs. Jaroli’s medical history, including the absence of complications from diabetes such as peripheral neuropathy, in Dr. Gelmon’s opinion, there were no contraindications for chemotherapy.

[136] Dr. Gelmon testified about the Oncotype Dx testing which provides an indication of the aggressiveness of a particular person’s cancer.

[137] She testified that the status of the lymph node was the most important determinant of the risk of cancer having spread and coming back at some point.

[138] Dr. Chiarotto estimated the risk that Mrs. Jaroli’s sentinel lymph node was positive was approximately 16%. Dr. Gelmon estimated the risk at 20%. Dr. Dueck had estimated the risk at 10%.

[139] According to Dr. Gelmon, the standard of care in 2014 for a patient who had unknown node negative cancer and an intermediate risk of recurrence based on Oncotype Dx testing was chemotherapy plus hormone therapy. She also testified that for patients with a known node negative and low Oncotype Dx score the standard of care was thought to be hormone therapy but that there were study results that suggested standard of care was chemotherapy plus hormone therapy. She disagreed with Dr. Chiarotto’s opinion that, in 2014, the use of chemotherapy with a risk score below 25 was known not to be beneficial. Dr. Gelmon testified that that was not known in 2014. Studies were ongoing in 2014 but, as the answers were not known, the standard of care in 2014 remained chemotherapy and endocrine therapy as set out by Cancer Care Ontario.

[140] Dr. Gelmon also testified that the specific regimen of chemotherapy recommended to Mrs. Jaroli met the standard of care. According to Dr. Gelmon, the testing undertaken before chemotherapy established that Mrs. Jaroli was a suitable candidate for chemotherapy with Taxol.

[141] She said that muscle and joint aches and pains are extremely common after the administration of Taxol and usually occur on the third day after treatment. Sensory neuropathy as a result of Taxol most commonly comes on with cumulative doses and is rare with a single dose.

[142] The cross-examination focused on whether chemotherapy with Taxol was “ overtreatment ” in an elderly patient with diabetes, like Mrs. Jaroli.

[143] Dr. Gelmon agreed that adding chemotherapy to estrogen receptor positive cancer with adjuvant endocrine therapy results in a very small reduction in the risk of recurrence. However, she stated, estrogen receptivity is not the only factor to consider. One factor alone is not definite in deciding the treatment.

[144] Cancer Care Ontario guidelines for 2014 stated that adjuvant chemotherapy may not be required in patients with HER2-, strongly ER+ and PR+ cancer with any of the following additional characteristics:

• lymph node -positive with micrometastasis
• T < 5mm, or
• an Oncotype Dx RS with an estimated distance relapse risk of less than 15% at 10 years.

[145] Dr. Gelmon said that, although some of those features are present in this case, Mrs. Jaroli did not fit all of them.

[146] Standard of care is treatment guidelines based on evidence. Dr. Dueck testified that Mrs. Jaroli received the treatment as recommended by the Ontario Cancer Guidelines in 2014.

[147] Dr. Gelman agreed that an Oncotype Dx testing score of 20 translated into a recurrence risk of 13% but clarified that, without knowing the node status, the risk was at least 13%.

[148] She said that the Oncotype Dx score was developed to determine whether the addition of chemotherapy would be of benefit. Dr. Gelmon testified that the standard of care for a score of 20 with a node negative would have been chemotherapy plus hormone therapy and that the standard of care for node positive would have been chemotherapy plus hormone therapy. As Mrs. Jaroli had a score of 20, with known an unknown node, the standard of care was chemotherapy plus hormone therapy.

[149] She agreed that peripheral neuropathy was a known side effect of Taxol but usually related to cumulative, rather than single, doses. Dr. Gelmon testified that it is “rare to see severe neuropathy after one dose”.

[150] She agreed that in selecting the chemotherapy regimen the medical oncologist weighs efficacy and toxicity. The Cancer Care Ontario guidelines for 2014 listed six different chemotherapy treatment regimens. A regimen without Taxol would involve increasing the dosage of the other drugs resulting in increased risk of cardiotoxicity and leukemia. She testified that the risk of peripheral neuropathy would have been different with a different chemotherapy regimen, but it might not have been completely avoided.

[151] Dr. Chiarotto’ s opinion with respect to standard of care was put directly to Dr. Gelman. The questions and Dr. Gelmon’s response are reproduced below:

Q. Dr. Chiarotto testified in this trial, Doctor and said the Doctor Dueck’s treatment with chemotherapy and in particular with Taxol, was too aggressive, and not warranted in a 72-year-old patient with comorbidities, hormonal positive cancer, without any of the traditional risk factors and given her Oncotype Dx score.

You disagree?

Yes, I disagree. I disagree, because we didn't know her node status, and that’s the biggest thing. When we're treating cancer, we’re trying to avoid recurrence and death. Not knowing the node status, put Dr. Dueck at a disadvantage to be able to give her a better recommendation. If her nodes had been positive, and she was in higher risk, then obviously that would have been different. In 2014, the standard of care, with an Oncotype recurrent score of 20 was chemotherapy, plus endocrine therapy. Therefore, that was standard. Although, Mrs. Jaroli had some comorbidities like diabetes, Dr. Dueck in her letters appeared to have considered them and there was no end organ damage at that time. Mrs. Jaroli has survival of greater than a year. So, there was no reason not to, and ultimately from my reading of the features, when Dr. Dueck talked about the Oncotype recurrence score, and the standard of care for an Oncotype recurrence score in 2014. When she talked about not knowing the nodal status. And when she talked about getting chemotherapy, she did consider the side effects, she talked about them, she advised Mrs. Jaroli about them. Mrs. Jaroli consented to treatment, underwent treatment, when Mrs. Jaroli had side effects, those were addressed. So, I think that Dr. Dueck’s care was appropriate.

Positions of the Parties

13. The Plaintiff

[152] Counsel for the Mrs. Jaroli submitted that none of the prognostic features of Mrs. Jaroli’s cancer represented high risk disease and that, as Dr. Dueck testified, treatment with chemotherapy was not mandatory or obligatory for all breast cancer patients. Chemotherapy and, particularly chemotherapy with Taxol, was not necessary given the risk of the known side effect of peripheral neuropathy in a patient who already had diabetes.

[153] Counsel for Mrs. Jaroli relied upon the testimony of Dr. Chiarotto who testified that, in 2014, patients with recurrence scores in the high range were given chemotherapy and that patients with recurrence scores below 25 were not. Dr. Chiarotto’s opinion was that there is no basis for chemotherapy and the benefit of adding chemotherapy to a patient like Mrs. Jaroli given her age and diabetes, was not significant enough to warrant chemotherapy.

[154] Counsel for Mrs. Jaroli submits that causation is made out. Although Mrs. Jaroli had diabetes, Dr. Dueck ruled out peripheral neuropathy prior to beginning chemotherapy. Mrs. Jaroli experienced symptoms consistent with peripheral neuropathy immediately after the administration of Taxol which has peripheral neuropathy as a known side effect. Even Dr. Dueck acknowledges, counsel said, that the immediate symptoms suffered by Mrs. Jaroli after administration of Taxol were the result of Taxol.

[155] Based on a number of decisions [8] counsel for Mrs. Jaroli submit that the range of general damages appropriate as compensation for Mrs. Jaroli’s current symptoms and limitations fall in the range of $110,000 to $140,000.

[156] As to the apportionment of liability between the hospital, which lost the lymph node, and Dr. Dueck, counsel for Mr. Jaroli submitted that both were equally at fault, 50%/50%, for Mrs. Jaroli’s injuries to her lower legs and feet.

14. The Defence

[157] Counsel for Dr. Dueck submitted that the evidence in this case established that Dr. Dueck met the standard of care. They submitted that Dr. Dueck acted carefully, cautiously, and exercised her clinical judgement in a manner that was consistent with medical science at that time. Counsel for Dr. Dueck also submit that Mrs. Jaroli has not adduced sufficient evidence to discharge her burden to demonstrate that the chemotherapy caused the issues she now complains of. Even if liability is established, counsel for Dr. Dueck submitted that the damages are minimal as Mrs. Jaroli’s difficulties with mobility and strength result largely from her age and or other health issues and are unrelated to the chemotherapy she received in 2014.

[158] Relying on Watson v. Soon, 2018 ONSC 3809 [9] counsel for Dr. Dueck submitted that the standard of care for a physician practicing in Ontario is that of a “normal prudent practitioner of the same experience”. It is not a standard of perfection; rather, the law provides that the professional will use reasonable care and skill.

[159] The absence of the sentinel lymph node placed Mrs. Jaroli and Dr. Dueck in “uncharted territory”. If the lymph node was positive, then chemotherapy was indicated. If the lymph node was negative, the Oncotype Dx score placed Mrs. Jaroli in a range in which it was not known whether chemotherapy was beneficial or not. Counsel for Dr. Dueck submitted that chemotherapy was not only reasonable but the best decision at the time as confirmed by the evidence of Dr. Gelmon and the Cancer Care Guidelines in 2014. As to the regime of chemotherapy, whether Taxol should be used, counsel submitted that treatment with Taxol was the “gold standard” in 2014, again relying on the Cancer Care Ontario guidelines.

[160] With respect to causation of Mrs. Jaroli’s peripheral neuropathy, counsel for Dr. Dueck submitted that the onus was on Mrs. Jaroli to establish, on a balance of probabilities, that, but for the negligence of Dr. Dueck, the injury would not have occurred.

[161] While counsel for Dr. Dueck acknowledged that Mrs. Jaroli has peripheral neuropathy, counsel argued that the evidence fell short of demonstrating that Mrs. Jaroli’s current difficulties were caused by the administration of Taxol. As to the evidence of Dr. Chiarotto, counsel argued that Dr. Chiarotto misinterpreted the conclusions reached by Dr. Hindle who performed the nerve conduction studies. While it is acknowledged that Taxol may cause peripheral neuropathy, as Mrs. Jaroli was informed, as Dr. Dueck and Dr. Gelmon testified, it is rare that a single dose of Taxol would cause peripheral neuropathy and that the side effects of Taxol were predictable with neuropathy occurring shortly after administration of the dose but resolving before the next cycle. Mrs. Jaroli’s current difficulties, counsel submitted, are more likely attributable to her osteoarthritis and other medical conditions.

[162] Relying upon such decisions as Addison v. Trillium Health Centre, 2005 CarswellOnt 4701 [10], Fulton v. Welland (City), 2006 CarswellOnt 7783 [11] and O’Bonsawin v. Parahis, [1993] O.J. No. 396 [12], counsel for Dr. Dueck submitted that damages should be assessed in the range of $25,000 to $45,000 for general damages.

[163] As to apportionment of liability between the hospital, which lost the lymph node, and Dr. Dueck, if liable, counsel for Dr. Dueck submitted that Dr. Dueck’s apportionment of fault would be, at most, 25%.

The Law

15. Liability

[164] The authorities relied upon by both parties establish a number of principles with respect to standard of care applicable to this case.

[165] Every medical practitioner must bring to his task a reasonable degree of skill and knowledge and must exercise a reasonable degree of care. He is bound to exercise that degree of care and skill which could reasonably be expected of a normal, prudent practitioner of the same experience and standing, and if he holds himself out as a specialist, a higher degree of skill is required of him than of one who does not profess to be so qualified by special training and ability . [13]

[166] Physicians are not held to the standard of perfection. At law, a physician’s conduct will be judged in light of the knowledge they ought to have reasonably possessed at the time of the alleged act or omission. The court must look at the steps taken and asked whether they conformed to what would be reasonably expected of a similarly situated medical professional. [14]

[167] Given the number of available methods of treatment from which medical professionals must at times choose, and the distinction between error and fault, a doctor will not be found liable if the diagnosis and treatment given to a patient corresponded to those recognized by medical science at the time, even in the face of competing theories. [15]

16. Causation

[168] The plaintiff must prove that the breach of the standard of care caused the plaintiff’s injury. The test for showing causation is the “but for” test. The plaintiff must show on a balance of probabilities that “but for” the defendant’s negligent act, the injury would not have occurred. [16]

Analysis and Decision

17. Liability

[169] I make the following findings.

[170] Mrs. Jaroli was mistaken as to her recollection of her conversation with Dr. Dueck when they first discussed treatment. I find that the nursing note which records that Mrs. Jaroli was “ leaning toward having chemo ” accurately records Mrs. Jaroli’s intention. I find that Dr. Dueck did not tell Mrs. Jaroli that chemotherapy would be “ over-treatment ”. I prefer Dr. Dueck’s testimony when in conflict with Mrs. Jaroli’s testimony. Dr. Dueck’s notes throughout her care of Mrs. Jaroli were detailed and comprehensive and I accept that those consultation notes accurately record Dr. Dueck’s observations and her interactions with Mrs. Jaroli.

[171] All medical witnesses who testified, the surgeon, Dr. Holmes and both experts, Dr. Chiarotto and Dr. Gelman, agreed that not knowing the status of the sentinel lymph node represented a “ difficult situation ”, “ challenging ”, “ unusual ”, as the status of the lymph node was the most important determinant of the risk of cancer returning.

[172] The consensus of the multidisciplinary treatment team was that Oncotype Dx testing was appropriate but did not consider treatment with an intermediate risk score. As Dr. Anthes testified, in 2014, it was up to the medical oncologist and the patient to decide if a patient with an intermediate risk score would require chemotherapy.

[173] There is no issue that the known side-effects of Taxol, including permanent and painful peripheral neuropathy, were fully discussed with Mrs. Jaroli who elected to have that treatment.

[174] The two experts disagreed on whether chemotherapy was warranted and whether treatment with Taxol was appropriate. When in conflict, I prefer the evidence of Dr. Gelmon but recognize that this situation, with the missing lymph node was, as Dr. Chiarotto agreed, the “ management of a difficult cancer patient ”. I prefer the evidence of Dr. Gelmon because of her greater expertise in the treatment of breast cancer and her research and education experience. At times, Dr. Chiarotto advanced positions that were not made out by the evidence such as his interpretation of Dr. Hindle’s clear conclusions on causation or arguing that Dr. Dueck had concluded that the lymph node was negative because Dr. Dueck sent the biopsy sample for Oncotpye Dx testing.

[175] I find, as both Dr. Dueck and Dr. Gelmon testified, that the effectiveness of chemotherapy in patients with an intermediate Oncotype Dx recurrence score was not known in 2014 and that, for Mrs. Jaroli, with an unknown lymph node status, there was at least a 13% recurrence risk, consistent with the recurrence risks estimated by Dr. Holmes (13-18%), Dr. Chiarotto (16%), and Dr. Gelmon (approx. 20%). The “best case” and “worst case” analysis undertaken by Dr. Dueck met the standard of care in Ontario according to Dr. Gelmon and was supported by the best practice Cancer Care Ontario Guidelines in 2014. Although, Dr. Chiarotto may not have followed the same course of conduct in 2014, his answer to the question reproduced at paragraph 76 above confirms that the difference in his opinion and the opinion of Dr. Gelmon arise from two experts differing on a question of clinical judgement in a difficult case.

[176] Similarly, the treatment with Taxol, the “gold standard”, met the standard of care in Ontario in 2014 in Dr. Gelmon’s opinion. Other treatments were known to be less effective in reducing the recurrence of cancer and had other serious side effects, cardiotoxicity and leukemia, including peripheral neuropathy. As Dr. Gelmon testified, Dr. Dueck ensured that Mr. Jaroli was fit for chemotherapy, had considered the diabetes – “ no end organ damage at that time ” and had advised Mrs. Jaroli of the enhanced risk posed by her diabetes. Dr. Gelmon’s opinion was that there were no contraindications for treating Mrs. Jaroli with Taxol.

[177] I find that the actions and recommendations of Dr. Dueck conformed to what would be reasonably expected of a similarly situated medical professional.

[178] The plaintiff has not established, on a balance of probabilities, that the defendant breached that standard of care in recommending chemotherapy and chemotherapy with Taxol to the plaintiff in 2014.

[179] As I find no negligence with respect to the conduct of Dr. Dueck, it is not necessary to apportion negligence between Dr. Dueck and the hospital who lost the lymph node.

18. Causation

[180] I make the following findings.

[181] Although Mrs. Jaroli had diabetes in 2014, with diabetic neuropathy in the past, there were no symptoms of peripheral neuropathy in 2014.

[182] Permanent and painful peripheral neuropathy is a known side effect of Taxol.

[183] Patients with diabetes are at a higher risk of developing peripheral neuropathy.

[184] On a balance of probabilities, Mrs. Jaroli’s immediate symptoms of neuropathy following the administration of Taxol in September 2014 were as a result of the Taxol.

[185] In March 2020, Dr. Hassan, the neurologist, diagnosed Mrs. Jaroli with peripheral neuropathy but did not know the cause.

[186] Dr. Hindle conducted nerve conduction studies in September 2020 and noted that Mrs. Jaroli had “ mild motor and moderate sensory neuropathy of the lower legs and feet that is likely secondary to diabetes and/or related to the chemotherapy medications …”.

[187] Dr. Dueck did not note any residual neuropathy in February 2015.

[188] Mrs. Jaroli has osteoarthritis which required a knee replacement in 2018 and a hip replacement in 2020.

[189] Mrs. Jaroli has used a cane in the past, prior to her treatment with Taxol, and now, a walker.

[190] Dr. Chiarotto’s opinion on causation was based on his conclusion that Dr. Hindle had stated that “ chemotherapy had the significant role in causing the ongoing nerve damage ”. That was not Dr. Hindle’s evidence.

[191] Dr. Gelmon testified that that it was extremely rare to get side effects from a single dose of Taxol but deferred to the opinion of the experts who said the cause was multifactorial.

[192] The plaintiff has the onus of establishing causation on a balance of probabilities. While I am satisfied that, based on the opinion of Dr. Dueck, that Mrs. Jaroli’s initial symptoms were caused by Taxol, I am not satisfied on a balance of probabilities that her current symptoms and restrictions are due to Taxol.

[193] There was no expert evidence before me to assist in determining whether Taxol, as opposed to other conditions such as diabetes, was the cause or a cause of the current difficulties. Dr. Hassan was the only neurologist who saw Mrs. Jaroli and he did not reach a conclusion on the cause of her neuropathy. Dr. Hindle’s opinion, “ likely secondary to diabetes and/or related to the chemotherapy medications …” does not assist me. Dr. Hindle’s opinion was not conclusive as it presented three possibilities: likely related to diabetes, or likely related to diabetes and chemotherapy, or likely related to chemotherapy. That the chemotherapy may be a cause of the peripheral neuropathy is not proof on a balance of probabilities. The plaintiff has not satisfied me that Taxol caused the current symptoms and that the current symptoms were not caused by other health conditions.

[194] I would have assessed general damages attributable to the symptoms arising from the initial side effects of Taxol at $25,000 if I had found a breach of the standard of care.

Conclusion

[195] The plaintiff’s action is dismissed.

[196] If costs are sought, the defendant may make costs submissions in writing limited to ten pages plus costs outline within 60 days of this decision. The plaintiff shall have 30 days from delivery of the defendant’s cost submissions to make her submissions, also limited to ten days plus costs outline. If no costs submissions are received within 60 days, then costs will be deemed settled.

“Original signed by”

The Hon. Mr. Justice W.D. Newton

Released: May 19, 2023

COURT FILE NO.: CV-16-0151-00 DATE: 2023-05-19 ONTARIO SUPERIOR COURT OF JUSTICE B E T W E E N: Carolyn Rose Jaroli Plaintiff

• and - Dorie-Anna C.C. Dueck Defendant TRIAL JUDGMENT Newton J. Released: May 19, 2023

Footnotes

[1] Taxol is a chemotherapy drug under the Taxane class of chemotherapy drugs also known as paclitaxel.

[2] Damage to the nerves in the extremities such as hands, feet and arms.

[3] Anthracycline – a class of chemotherapy drugs.

[4] As will be explained later, examination of the sentinel lymph node, which drains the breast in which the cancer was located, is an important diagnostic step in determining whether cancer has spread from the breast.

[5] The study that both experts referred to which sought to resolve the uncertainty about the benefits of chemotherapy to patients with an Oncotype Dx score in the intermediate range was not published until 2018 in the New England Journal of Medicine. This was the TAILORx study.

[6] Optimal Systemic Therapy for Early Female Breast Cancer, report Date: September 30, 2014.

[7] Human epidermal growth factor receptor 2 is a protein on the surface of cells that helps them grow, if there are too many copies of the HER2 gene in a cell this can result in tumor growth.

[8] Maceachern v. TFG Inc., 2018 ONSC 309, Miller v. Devenz, [2001] O.J. No. 4084, Cartner v. Burlington (City), [2008] O.J. No. 2986, Przelski v. Ontario Casino Corp., [2001] O.J. No. 3012, Ivens v. Lesperance, 2012 ONSC 4280, and Kania v. 1618278 Ontario Inc. c.o.b. as Heart and Crwon Irish Pubs, 2015 ONSC 7042.

[9] 2018 ONSC 3809 at paras. 22-24.

[10] 2005 CarswellOnt 4701 at paras. 27-29.

[11] 2006 CarswellOnt 7783 at paras. 12-19.

[12] [1993] O.J. No. 396 at p. 7.

[13] Crits v. Sylvester, [1956] O.R. 132 at para. 13.

[14] Watson v. Soon, 2018 ONSC 3809 at para. 24.

[15] Laponte c. Hopital Le Gardeur, [1992] S.C.J. No. 11 at para. 31.

[16] Clements (Litigation Guardian of) v. Clements, 2012 SCC 32 at para. 8.