COURT OF APPEAL FOR BRITISH COLUMBIA

Citation:	Bohun v. Segal,
	2008 BCCA 23

Date: 20080122

Docket: CA034887

Between:

Pamela Bohun

Respondent

(Plaintiff)

(Appellant on Cross Appeal)

And

Dr. Jean Michael Segal

Appellant

(Defendant)

(Respondent on Cross Appeal)

Before:	The Honourable Madam Justice Kirkpatrick
	The Honourable Mr. Justice Frankel
	The Honourable Mr. Justice Tysoe

 

J. M. Lepp, Q.C.  and C.L. Khanna	Counsel for the Appellant
S.H. Ashcroft and C. Sweet	Counsel for the Respondent
Place and Date of Hearing:	Vancouver, British Columbia
13 November 2007
Place and Date of Judgment:	Vancouver, British Columbia
22 January 2008

 

Written Reasons by:

The Honourable Madam Justice Kirkpatrick

Concurred in by:

The Honourable Mr. Justice Frankel The Honourable Mr. Justice Tysoe

Reasons for Judgment of the Honourable Madam Justice Kirkpatrick:

[1]                The central issue in this appeal is whether the trial judge erred in principle in adopting the material contribution test of causation.  The case at trial concerned the delayed diagnosis of breast cancer.  The trial judge found that when the plaintiff, Pamela Johnston (who was known as Pamela Bohun at the time the writ of summons was filed), first saw the defendant, Dr. Segal, she was suffering from undiagnosed breast cancer.  The trial judge found that, at that time, Ms. Johnston had about a 79% chance of survival and a 21% chance of death from the disease.  The trial judge found that Dr. Segal was in breach of his duty of care to Ms. Johnston by failing to perform a biopsy which, if performed, would have disclosed the breast cancer and resulted in the removal of the tumour at that time.  The tumour was later excised.  The trial judge found that the delay in diagnosis decreased Ms. Johnston's chance of survival.

[2]                Ms. Johnston claimed damages for her reduced life expectancy or "lost years" and her increased pain and suffering during those years.

[3]                The trial judge concluded that, since the plaintiff could not prove whether the cancer had metastasized before or after she first saw Dr. Segal, he ought to adopt the "material contribution" test of causation.  He found in favour of the plaintiff.

[4]                Dr. Segal appeals from the finding of liability.  Ms. Johnston filed a cross appeal on 2 April 2007 from the trial judge's assessment of damages.  She died prior to the hearing of the appeal.

[5]                The essential facts of the case are not in dispute.

[6]                On 12 April 2001, Ms. Johnston attended at the office of her family physician, Dr. Sennewald, because she was concerned about a breast lump she had noticed a few days earlier.  The expert medical evidence was that the size of the tumour is a critical factor in the diagnosis, treatment and prognosis of breast cancer.  Ms. Johnston testified that the lump was then the size of a pea.  Dr. Sennewald palpated the breast.  Her impression was that the lump was approximately 2 cm in size, which she recorded in Ms. Johnston's chart.  The trial judge accepted Dr. Sennewald's evidence.

[7]                Dr. Sennewald considered that Ms. Johnston probably had fibrocystic breasts, a benign diagnosis. However, because of her patient's concern, Dr. Sennewald referred Ms. Johnston for an ultrasound and mammogram, which were scheduled for 8 May 2001.

[8]                On 8 May 2001, prior to ultrasound and mammogram tests, Ms. Johnston had a complete physical examination by Dr. Sennewald.  Ms. Johnston testified that she told Dr. Sennewald at that time that the lump had grown from the size of a pea to approximately the size of a quarter.  Dr. Sennewald's clinical notes indicate that there had been no change in the size of the lump.  The trial judge again accepted Dr. Sennewald's evidence.

[9]                The mammogram report was interpreted as showing "[D]ense irregular fibrocystic stoma.  No evidence of mass or malignant change identified".

[10]            The ultrasound report showed a 24 x 13 x 23 mm solid, irregular mass.  The ultrasound was interpreted as showing a "[r]ight breast mass, just above and behind the nipple.  May be a cyst with a clot or a fibroadenoma.  Biopsy is recommended, however, for further assessment."

[11]            Dr. Sennewald testified that, after reviewing the mammogram and ultrasound results, she referred Ms. Johnston to the defendant, Dr. Segal, a general surgeon who specializes in the treatment of breast cancer, to "rule out cancer and for biopsy or as per [his] advice".  Dr. Sennewald was a defendant at trial.  The trial judge found that she met the standard of care of a general practitioner and dismissed the action against her.  There is no appeal from that order.

[12]            Ms. Johnston first saw Dr. Segal on 15 June 2001.  He examined her breast and found a mobile, smooth, discrete mass that he measured with a ruler to be 2.5 cm in size.  His impression was that Ms. Johnston had a benign right breast mass likely to be a fibroadenoma.

[13]            On 15 June 2001, Dr. Segal wrote to Dr. Sennewald and advised her that Ms. Johnston's "benign right breast mass" would be observed over the following three months.  Ms. Johnston was to contact him if there were any changes.

[14]            The trial judge found that Dr. Segal did not follow his standard practice of recommending that a biopsy be performed and that the failure to do so was a breach of the standard of care.  No appeal is taken from that finding.

[15]            Ms. Johnston missed her next scheduled appointment with Dr. Segal on 24 September 2001.  She saw him for follow-up on 22 October 2001.  Dr. Segal's notes indicate that Ms. Johnston told him that the lump was increasing in size.  His examination, again with a ruler, indicated that the lump was still 2.5 cm in size.  He observed that the breast was tender and made arrangements to have the lump removed.

[16]            On 10 January 2002, Dr. Segal performed an excisional biopsy.  The pathological size of the tumour was 4.5 cm in size.  The trial judge accepted that Dr. Segal's clinical assessment of 2.5 cm to 3 cm at the time of surgery was different from the pathological size because clinical assessments cannot measure the microscopic extensions of the tumour.  The pathological findings of tumour extension necessitated further surgery to ensure that all of the tumour was removed.

[17]            On 28 January 2002, Dr. Segal performed a right partial mastectomy and axillary dissection (also known as breast conserving surgery).  The pathology report following that surgery indicated that there was no evidence of residual malignancy and eight nodes were found to be negative for metastatic carcinoma.  The surgery was followed by radiation therapy.

[18]            Ms. Johnston underwent four cycles of chemotherapy from May to June 2002, followed by radiation therapy in July 2002.

[19]            Ms. Johnston married in May 2003.  On 5 May 2004 she gave birth to her daughter.  The trial judge described the events that followed at paras. 29–30 of his reasons (2007 BCSC 269, 46 C.C.L.T. (3d) 138):

            In April 2004, near the end of her pregnancy she felt something at the source of her earlier tumour.  An ultrasound was negative.  In June 2004, another ultrasound test was performed followed by a needle biopsy which determined that her breast cancer had recurred at the same site.  A treatment plan was discussed and it was determined that both breasts should be removed.

            Prior to surgery taking place, however, test results from a CT scan showed that the cancer had spread to her lungs.  Surgery was no longer a viable treatment option.  By July 2006, the cancer had spread to Ms. Johnston’s hip, liver and bone area.  Tumours had grown in her lungs, as had the lump in her breast.  She is now in a palliative care program.  Her prognosis is very poor and she has but months to live.

[20]            Ms. Johnston died in June 2007, approximately four months after the trial.

[21]            As I have noted, the central issue at trial was the effect of the delay in diagnosis between June 2001 (when Ms. Johnston first saw Dr. Segal) and January 2002 (when the excisional biopsy was performed).

[22]            The defendants called Dr. Olivotto, a radiation oncologist at the B.C. Cancer Agency (the "Cancer Agency"), who was the only expert qualified to give evidence as to how a delay in diagnosis affects the prognosis of patients with breast cancer.

[23]            The plaintiff's expert surgeon, Dr. Woo, was qualified to give an opinion on the standard of care.  Dr. Woo's practice is to leave specific discussions of a patient's prognosis to the oncologists at the Cancer Agency.

[24]            There was no dispute that a delay in diagnosis and treatment increases the risk of relapse of the cancer and death.  Dr. Olivotto testified that the ten-year risk of death from breast cancer for a tumour 2.1 cm to 3.0 cm in size was 21%, and for a tumour 3.1 cm to 5.0 cm the risk was 25%.

[25]            The trial judge summarized the scientific and medical evidence and his findings in respect of the effects of delay in diagnosis at paras. 89–92 of his reasons:

            It is a complicated task to integrate the effects on risk estimates of all the clinical, pathology and treatment factors to determine a valid estimate for the risk of recurrence or death from breast cancer for an individual woman.  In recent years, a web-based algorithm has been developed that provides a convenient and reliable way to incorporate an individual woman’s clinical and pathological features at the time of diagnosis with the estimates of the [effects] of various chemotherapy and hormonal treatment that she might receive.  The program known as “ADJUVANT!” is accepted as a reliable predictor of ultimate outcomes.

            Dr. Olivotto used ADJUVANT! to calculate the risk of relapse from breast cancer for a woman whose age and cancer was that of Ms. Johnston’s.  The 10-year risk of death for a woman with a tumour of 2.1 cm to 3.0 cm was 21%.  For a tumour measuring 3.1 cm to 5.0 cm, the 10-year risk of death was 25%.  Growth from 2.5 cm to 4.0 cm would increase a young woman’s risk of spread or death from breast cancer about 3% to 4%.  A change from 3.0 cm to 4.5 cm as exists in this case, would increase the risk of death by approximately 2% to 3%.  Stated another way, if Ms. Johnston’s tumour had been removed in June 2001, it would have increased her chances of survival by 10% to 15%.

            ADJUVANT! does not take into account the form of Ms. Johnston’s cancer.  As previously noted, ACC [adenoid cystic carcinoma] is a very rare tumour which accounts for less than 1% of all breast cancers.  Research indicates that ACC tumours are slow growing and rarely metastasize.  Patients with such tumours generally have a more favourable prognosis than other breast cancer patients.  Dr. Olivotto did not reduce the risk factors because he considered the tumour a variation of ACC, which he believed was more likely to act like other cancers.  He acknowledged that the rareness of the tumour made the determination more difficult.

            I accept generally Dr. Olivotto’s evidence in regard to the impact that delay of the diagnosis had on Ms. Johnston.  Even if the tumour had been diagnosed in June, as it should have been, there was a significant risk that she would die.  The growth of the tumour subsequent to June 15, 2001 reduced her chance of survival by a further 10% to 15%.  This number must be adjusted to take into account the nature of her cancer.  In making this adjustment, I am aware that the pathologist suggested that this was a variant of ACC of which little is known.  However, given the evidence that ACC is rarely fatal, I find that if Dr. Segal had removed the tumour in June 2001, Ms. Johnston had a 20% increased chance of survival.

[Emphasis added.]

[26]            It appears that the trial judge confused the plaintiff's increased risk of death with her decreased likelihood of survival.  For example, he noted that the growth of the tumour subsequent to 15 June 2001 reduced the plaintiff's likelihood of survival by 10–15%.  In fact, based on the scientific evidence accepted by the trial judge, the plaintiff's risk of death was increased by a relative 10–15% due to the delay in diagnosis.  Her likelihood of survival decreased by a nominal amount, 3–4%, which is a relative decrease of 3.8–5%, due to the delay.  This error is an unintended transposition of two easily confused terms (risk of death versus likelihood of survival).  As will be seen, this error is of no consequence in the final analysis of causation.  However, in these reasons, I have chosen to correct the unintended transposition, and I rely on the facts that the trial judge must have intended to find, namely that the plaintiff's risk of death increased by a relative 10–15% due to the delay in diagnosis.

[27]            Following his erroneous expression as to the plaintiff's likelihood of survival, the trial judge adjusted the figure from 10–15% to 20% to account for the rare type of cancer suffered by the plaintiff.  By properly expressing the trial judge's finding as to the risk of death versus likelihood of survival, it is clear that the plaintiff's relative risk of death was increased by 20% due to the missed diagnosis and the type of cancer she had.

[28]            As I have noted, the trial judge found that Dr. Segal breached the standard of care by failing to recommend a biopsy in June 2001.  He found that the plaintiff would have undergone the procedure and that the cancer would have been detected.  He then considered whether the failure to detect the cancer in June 2001 caused damage to the plaintiff.

[29]            The trial judge first considered the principles of causation recently restated by the Supreme Court of Canada in Resurfice Corp. v. Hanke, 2007 SCC 7, [2007] 1 S.C.R. 333.

[30]            The trial judge described the parties' positions at paras. 71 and 75:

            Ms. Johnston submits Dr. Segal’s failure to discover the cancer in June 2001 was a material contribution to her injury and loss.  She says that the plaintiff’s injury clearly falls within the ambit of risk created by Dr. Segal’s breach of the standard of care.  She submits that liability may be imposed, even though the “but for” test is not satisfied, because it would offend basic notions of fairness and justice to deny liability in these circumstances.

[….]

            The defendants submit the plaintiff has not proved that “but for” the alleged delay there would not have been a reoccurrence of Ms. Johnston’s breast cancer.  They submit that the evidence has established that the more likely cause of the reoccurrence and spread is the breast cancer itself.

[31]            He concluded his analysis of causation at paras. 93–95:

            This discussion returns us to the submissions of the parties on causation.  The defendant submits that Ms. Johnston has not proven that “but for” the alleged delay she would not have had a recurrence of her breast cancer.  In their submission, the most likely cause of the recurrence and spread is the breast cancer itself.  They submit that at best, Ms. Johnston has established a lost chance, and that such a loss is not sufficient to establish causation: Laferriere v. Lawson, [1991] 1 S.C.R. 541.

            I do not agree.  This is not a “lost chance” case, but a causation case.  This case meets the special circumstances that require an application of the material contribution test.  In the language of Resurfice, it is impossible for Ms. Johnston to prove that Dr. Segal’s negligence caused her injury using the “but for” test.  The impossibility is due to factors that are outside of her control.  While it is known that the cancer metastasized to other parts of Ms. Johnston’s body prior to the first surgery in January 2002, it is impossible, due to the current limits of scientific knowledge, to know whether that migration took place before or after June 2001.

            Dr. Segal’s negligence caused the delay in diagnosis and treatment.  Any delay in the treatment of breast cancer increases the risk.  The delay in treatment materially contributed to the fatal outcome Ms. Johnston now faces.  Ms. Johnston’s injury falls within the ambit of the risk created by Dr. Segal’s negligence when he failed to do a biopsy in June 2001. 

[32]            The trial judge discussed damages at paras. 97–98:

            The measure of damages is subject to any contingencies that might reduce them.  Ms. Johnston is only entitled to be returned to the position she would have enjoyed, with all its attendant risks and shortcomings, but for Dr. Segal's negligence:  Athey v. Leonati, [1996] 3 S.C.R. 458.

            The contingency of unsuccessful treatment and recurrence must be considered and taken into account in the assessment of damages.  I have found that if Ms. Johnston's condition had been properly diagnosed in June 2001 that her chances of survival would have increased [by] 20%.  Except for the award for psychological damage, the damage awards must be discounted by a global contingency of 80% to reflect that fact.

[33]            The trial judge then assessed Ms. Johnston's damages which are summarized at paras. 117–118:

            I award the plaintiff the following sums:

            The above awards are subject to an 80% deduction to reflect the contingency that Ms. Johnston may not have survived even if Dr. Segal had properly diagnosed her cancer in June 2001.  This reduces the award to $54,514.67.  In addition, I award Ms. Johnston $25,000 in psychological damages, which award is not subject to deduction.  Judgement is awarded against Dr. Segal for $79,521.52.

Arguments on Appeal

[34]            The appellant's fundamental argument is that the trial judge erred in principle when he found Dr.Segal's delay in treatment caused the harm even though the relative increase in the risk of harm from that delay was only 20%.

[35]            The respondent cross-appeals on the basis that the trial judge erred in principle in reducing by 80% her damages for non-pecuniary loss, past wage loss, loss of future earning capacity and special damages, and in awarding the amounts he did for non-pecuniary damages, past wage loss and future earning capacity.

[36]            Dr. Segal, as respondent on the cross-appeal, concedes that the trial judge erred in reducing Ms. Johnston's damages by 80%.  Based on the principles enunciated in Athey v. Leonati, [1996] 3 S.C.R. 458, Dr. Segal agrees that once causation is established, a defendant is fully liable for the damages suffered by a plaintiff subject to any negative contingencies to be applied.  Dr. Segal contends that in this case, if causation were established, the appropriate negative contingency would be 21% based on the fact that Ms. Johnston already had a 21% chance of dying at the time the diagnosis should have been made.  Ms. Johnston's counsel urged a 10% negative contingency based on Ms. Johnston's existing 21% risk of death, less 11% to take into account her relatively rare and rarely fatal form of breast cancer.

[37]            Because I hold the view that the trial judge erred in principle in finding causation, I need not discuss the assessment of damages, other than to say that I agree that the trial judge erred in reducing damages in the manner he did as offending well-established principles of damage assessment.  In my opinion, the trial judge conflated the evidence in respect of causation with the appropriate negative contingency applicable in determining the appropriate measure of damages.

[38]            The appellant, Dr. Segal, conceded that, regardless of the success of the appeal, Ms. Johnston remains entitled to the $25,000 awarded to her for the psychological damages she suffered due to the failure to diagnose her condition.  Dr. Segal concedes that the award of those damages is not contingent on a finding of causation in that Dr. Segal accepts that Ms. Johnston experienced psychological distress from the knowledge of her missed diagnosis.

[39]            I turn now to the central issue, causation.

Causation

[40]            As I have noted, the trial judge referred to the recent Supreme Court of Canada decision in Resurfice Corp. v. Hanke, in which the court, per McLachlin C.J., summarized the applicable principles of causation:

20        Much judicial and academic ink has been spilled over the proper test for causation in cases of negligence.  It is neither necessary nor helpful to catalogue the various debates.  It suffices at this juncture to simply assert the general principles that emerge from the cases.

21        First, the basic test for determining causation remains the "but for" test.  This applies to multi-cause injuries.  The plaintiff bears the burden of showing that "but for" the negligent act or omission of each defendant, the injury would not have occurred.  Having done this, contributory negligence may be apportioned, as permitted by statute.

22        This fundamental rule has never been displaced and remains the primary test for causation in negligence actions.  As stated in Athey v. Leonati, at para. 14, per Major J., "[t]he general, but not conclusive, test for causation is the 'but for' test, which requires the plaintiff to show that the injury would not have occurred but for the negligence of the defendant."  Similarly, as I noted in Blackwater v. Plint, at para. 78, "[t]he rules of causation consider generally whether 'but for' the defendant's acts, the plaintiff's damages would have been incurred on a balance of probabilities."

23        The "but for" test recognizes that compensation for negligent conduct should only be made "where a substantial connection between the injury and defendant's conduct" is present.  It ensures that a defendant will not be held liable for the plaintiff's injuries where they "may very well be due to factors unconnected to the defendant and not the fault of anyone": Snell v. Farrell, at p. 327, per Sopinka J.

24        However, in special circumstances, the law has recognized exceptions to the basic "but for" test, and applied a "material contribution" test.  Broadly speaking, the cases in which the "material contribution" test is properly applied involve two requirements.

25        First, it must be impossible for the plaintiff to prove that the defendant's negligence caused the plaintiff's injury using the "but for" test.  The impossibility must be due to factors that are outside of the plaintiff's control; for example, current limits of scientific knowledge.  Second, it must be clear that the defendant breached a duty of care owed to the plaintiff, thereby exposing the plaintiff to an unreasonable risk of injury, and the plaintiff must have suffered that form of injury.  In other words, the plaintiff's injury must fall within the ambit of the risk created by the defendant's breach.  In those exceptional cases where these two requirements are satisfied, liability may be imposed, even though the "but for" test is not satisfied, because it would offend basic notions of fairness and justice to deny liability by applying a "but for" approach.

[41]            Lord Hoffmann recently stated the English equivalent of the "but for" test in Barker v. Corus, [2006] UKHL 20, [2006] 3 All E.R. 785 at para. 1:

The standard rule is that it is not enough to show that the defendant's conduct increased the likelihood of damage being suffered and may have caused it.  It must be proved on a balance of probability that the defendant's conduct did cause the damage in the sense that it would not otherwise have happened.

[Emphasis in original.]

[42]            The medical and scientific evidence in the case at bar was unique in that it provided highly accurate predictions of the increased likelihood of death depending on the size of the breast cancer tumour.

[43]            It was a matter of no controversy that a diagnosis of breast cancer alters the prognosis of the patient.  Dr. Olivotto testified that life expectancy following a diagnosis of breast cancer is determined by a number of factors:

·           age of the patient;

·           whether the tumour has spread to the lymph nodes under the arm;

·           the size of the tumour; and

·           certain features of the tumour such as cell grade or the degree of microscopic abnormality.

Both Dr. Olivotto and Dr. Woo considered the size of the tumour at the time it could have been diagnosed to be an important factor.

[44]            In his medical legal report, Dr. Olivotto outlined the various factors that are taken into account in arriving at a prognosis:

The prognosis of breast cancer is related to a number of clinical and pathological features that can be determined at the time of diagnosis.  The factors which have most consistently been demonstrated to influence the subsequent likelihood of relapse or death from breast cancer include the number of involved axillary lymph nodes, the size of the primary tumor, the tumor's grade (a measure of how abnormal the cells look on microscopic examination, typically scored on a scale of 1 to 3) and the presence of lymphatic or vascular space invasion in the tumor.  Patients who are younger (age <40 years) and those with Estrogen Receptor (ER) negative tumors also have a higher risk of recurrence and death.  Various publications from the Breast Cancer Outcomes Unit, as well as elsewhere, have confirmed that these features can reliably be used to predict the future outcome after a diagnosis of breast cancer.

[45]            In his evidence at trial, Dr. Olivotto confirmed that the pathological measurement of the tumour is closely associated with outcomes.

[46]            Dr. Segal agreed in cross-examination that tumour size directly correlates with survival.

[47]            As can be seen from the trial judge's summary of the scientific and medical evidence, a unique feature of this case was the availability of the ADJUVANT! prognostic tool.  Dr. Olivotto testified at some length as to the ADJUVANT! program.  He stated that the program was shown to predict, within one per cent, the outcomes for patients with breast cancer. As Dr. Olivotto explained, the algorithm clusters the tumours into groups of less than one centimetre; 1 to 2 centimetres; 2.1 to 3 centimetres; 3.1 to 5 centimetres, and so on.  When applying the ADJUVANT! model to Ms. Johnston's circumstances, Dr. Olivotto inputted a tumour of between 2.1 to 3 centimetres and then stated:

[…] when we incorporate the risk of dying from the breast cancer minus the potential benefit of chemotherapy it comes to about a 21% chance of mortality, or, in other words, a 79% chance of being alive 10 years later.  If the tumor was four-and-a-half centimetres but otherwise the same characteristics that were seen in the pathology report:  grade II, ER negative, 34-year-old woman—it—it comes out to—it was about 24-and-a-half per cent and I round it up to 25% chance of death 10 years from diagnosis, or about a 75% chance of being alive, and that's including the benefits of chemotherapy that she received.  So, in—in summary, about a 4% difference if the growth was from two-and-a-half to four-and-a-half centimetres.  If the growth was less than that then the magnitude of benefit of adverse effect on survival would be a bit lower, so somewhere between 1 and 4% is probably—probably reality.

The trial judge accepted Dr. Olivotto's explanation as to the application of the ADJUVANT! program.  Alive to the difference between clinical and pathological measurement, and the need to track tumour growth by reference to one method of measurement, the trial judge accepted expert opinion as to the likely pathological size of the tumour in June 2001 and incorporated in his own analysis tumour growth of either 2.5 cm to 4.0 cm or 3.0 cm to 4.5 cm.  Depending on which set of numbers is chosen, the increase in absolute risk of death fluctuates by, at most, one per cent and does not alter the analysis of causation.

[48]            The trial judge was aware that tumour size is key in determining prognosis.  He noted at paras. 86–87 of his reasons:

            All witnesses agreed that a delay in the diagnosis of breast cancer is associated with a poor outcome.  Delays of diagnosis allow a tumour to enlarge and spread and for the cancer to travel to other parts of the body where it may for some years sit dormant before recurring.

            The prognosis of breast cancer is related to a number of clinical and pathological features including the size of the primary tumour, the number of involved axillary lymph nodes, the tumour’s grade and the age of the patient.  Patients who are younger than 40 years old have a higher risk of recurrence and death.

[Emphasis added.]

[49]            The evidence before the trial judge, and accepted by him, established that the delay in diagnosis increased Ms. Johnston's risk of death from breast cancer from 21% (her risk from dying from breast cancer on 15 June 2001 when the tumour ought to have been diagnosed) to 23 or 24% (rounded to 25%, as explained earlier).  In other words, accepting the trial judge's findings of fact, and his allowance for the rare type of cancer the plaintiff had, the missed diagnosis relatively increased the plaintiff's risk of death by 20% and in absolute terms the plaintiff's risk of death rose from 21% (if the tumour had been diagnosed and removed immediately) to approximately 25%.  That is, a 4% absolute increase in the plaintiff's risk of death represents an approximate 20% relative increase.  The 20% relative increase in the plaintiff's risk of death represented a causation probability of 20%.

[50]            The trial judge placed critical emphasis on the 21% figure, and on the increase to 25%, which were statistical probabilities indicating the increasing risk of death for Ms. Johnston, who had a growing tumour in her breast. Having accepted this medical and statistical evidence, the trial judge had a sufficient and appropriate basis for conducting the “but for” analysis.

[51]            However, the trial judge anchored his decision to apply the material contribution test in the fact that “it is impossible […] to know whether the migration took place before or after June 2001” (para. 94). This solitary statement, which appears late in his reasons, propelled the remainder of his causation analysis, but completely devalued the significance of the ADJUVANT!-generated evidence, which the trial judge accepted and used as the basis for his earlier statistical exposition of the plaintiff’s increased risk of death due to her enlarged tumour.  The weight of the medical evidence accepted by the trial judge was that the size of the tumour is predictive of the probability of recurrence, spread and death.  In other words, a prognosis generated by ADJUVANT! incorporates the potential eventuality of migration or metastasis.

[52]            The appellant thus contends, and I agree, that based on the evidence of Dr. Olivotto and the application of the ADJUVANT! program to the circumstances that confronted the plaintiff, the defendant, while obviously not obliged to do so, had disproved causation.  In order for the plaintiff to succeed, she had to prove that it was more probable than not that proper and timely diagnosis and treatment would have prevented her loss – namely, that she would likely have lived longer had Dr. Segal not been negligent (see Hotson v. East Berkshire Area Health Authority, [1987] 2 All E.R. 909 (H.L.)). To state it another way, Ms. Johnston had to establish that Dr. Segal’s conduct made it more probable than not that the delayed diagnosis of her cancer would cause her death to occur earlier than it would have but for Dr. Segal’s negligence. As Lord Hoffmann stated in Barker v. Corus, it was not enough to show that the defendant's conduct increased the likelihood of damage and may have caused it.  The evidence of causation in this case fell far short of proof on a balance of probabilities.

[53]            Having failed to establish causation on the available "but for" test, the causation analysis ought to have come to an end. It was not open to the plaintiff to prove, or to the trial judge to consider, the material contribution test. As stated in Resurfice, it must be impossible to prove negligence using the "but for" analysis before resort can be made to the material contribution analysis.  I do not read Resurfice to mean that, because a plaintiff fails to prove causation on the "but for" analysis, a plaintiff may then resort to the less stringent material contribution test. As this Court recently stated in B.S.A. Investors Ltd. v. DSB, 2007 BCCA 94, 69 B.C.L.R. (4^th) 292, leave to appeal to S.C.C. requested, where the reasons of the trial judge indicate that the plaintiff could not meet the burden of proving causation, then the plaintiff's action should be dismissed (at para. 33).

[54]            It follows that I would allow the appeal and dismiss the cross-appeal except to the extent agreed to by the appellant, namely the preservation of the $25,000 award for psychological damage suffered by Ms. Johnston from the knowledge of the delayed diagnosis.

“The Honourable Madam Justice Kirkpatrick”

I agree:

“The Honourable Mr. Justice Frankel”

I agree:

“The Honourable Mr. Justice Tysoe”