Most failed delayed-cancer-diagnosis cases fail at the same point: not on liability, not on the medicine being a breach of the standard of care, but on causation. The plaintiff must prove on a balance of probabilities that earlier diagnosis would have changed the outcome. Where the cancer was already metastatic at the time the diagnosis was missed, the patient would have died regardless of when the diagnosis was made. The negligence may have caused additional suffering. It does not, on the legal framework, cause the death.
Tripp v Ross, 2023 MBKB 173, is a useful illustration. The case was decided in Manitoba, but the underlying causation framework (the “but-for” test articulated in Clements v Clements, 2012 SCC 32) is the same across Canadian common law jurisdictions, including Ontario. The case is also notable for its split outcome: the wrongful death claim was dismissed on causation, but the trial judge awarded $75,000 in pain-and-suffering damages for the additional suffering the delay caused during the period the patient lived.
This is a useful doctrinal reference for delayed-cancer-diagnosis cases, where the realistic outcome often depends less on the existence of negligence than on the natural history of the underlying disease.
The substantive case
Mr. Tripp was a 53-year-old electrician in Manitoba. In December 2017, he presented to his family physician with rectal bleeding and abdominal cramps. He was referred to a general surgeon, Dr. Ross, who saw him at the end of December and recommended a colonoscopy.
The colonoscopy was performed on January 12, 2018. The surgeon found and removed five polyps. The pathology report identified one of the polyps as having low-grade dysplasia, which is a recognized precursor of adenocarcinoma. The surgeon advised Mr. Tripp at follow-up that the polyps had been aggressive and recommended a return appointment in one year.
The surgeon’s admitted negligence is the heart of the case. Once he found the five polyps, he assumed those were the source of Mr. Tripp’s bleeding and did not continue the colonoscopy. Had he continued, he would have seen the tumour in the descending colon. The case proceeded to trial on causation only; liability was admitted.
Between March and August 2018, Mr. Tripp had episodic abdominal pain and rectal bleeding. He saw his family physician on August 1, who ordered blood work that revealed low hemoglobin and iron deficiency consistent with chronic blood loss. He was referred back to the surgeon, who saw him on August 10. A barium enema showed a tumour in the descending colon. A CT scan confirmed the tumour and identified enlarged regional lymph nodes.
Surgery was performed on October 9, 2018, just over nine months after the original colonoscopy. The extent of the surgery indicates how far the disease had progressed: the tumour was removed along with 40 percent of the pancreas, the spleen, and all but a foot of the lower bowel. The tumour had grown into the pancreas and spleen and could not be completely removed.
The post-operative course was difficult. Mr. Tripp underwent multiple rounds of chemotherapy. In November 2018, he was admitted to hospital for 11 days for a bowel perforation. Imaging in December 2018 raised concern for liver metastases. In January 2019, his pancreas failed, producing insulin-dependent diabetes that was difficult to control because of the steroids he required as part of his chemotherapy.
Mr. Tripp stopped working in December 2019. He died on February 20, 2022, approximately four years after the initial missed diagnosis.
The causation question
The trial focused on a single causation question: would Mr. Tripp have likely survived the cancer if it had been diagnosed in January 2018 rather than August 2018?
The answer turned on whether the cancer had already metastasized at the time the diagnosis should have been made. Colon cancer is generally treatable when the disease is local; once it has metastasized to distant organs (most commonly the liver), the prognosis becomes terminal.
Both sides called medical oncologists as causation experts. There was substantial agreement between them on the key clinical facts:
- Colon cancer is slow-growing
- The tumour found in October 2018 had been present for a long time and would have been present in January 2018
- Colon cancer may be curable where the spread is local but becomes fatal once it has metastasized
- In Mr. Tripp’s case, the spread to the liver was the feature that made the disease incurable
The disagreement was about when the metastasis had occurred. The trial judge accepted the evidence that Mr. Tripp’s cancer was likely already metastatic at the time the diagnosis should have been made in January 2018. On that finding, earlier diagnosis would not have changed the eventual outcome. The wrongful death claim was dismissed.
The pain-and-suffering award
The trial judge did not dismiss the case in its entirety. The medical evidence established that the delay had exacerbated Mr. Tripp’s suffering during the period he lived after the eventual diagnosis. The surgical recovery was longer and more painful than it would have been with earlier intervention. The chemotherapy regimen was more intensive. The complications (the bowel perforation, the pancreatic failure, the insulin-dependent diabetes) all reflected the more advanced state of the disease at the time of treatment.
The trial judge found that even if Mr. Tripp would have ultimately died of cancer regardless of when the diagnosis was made, the delay had caused additional suffering that he would not otherwise have experienced. The defence conceded the point in principle, with some disagreement on quantum.
The trial judge awarded $75,000 in damages for pain and suffering.
The doctrinal framework: but-for causation in cancer cases
The Canadian common-law framework for causation in negligence cases is articulated in Clements v Clements, 2012 SCC 32. The Supreme Court reaffirmed the “but-for” test as the default approach to causation: the plaintiff must prove on a balance of probabilities that the harm would not have occurred but for the defendant’s negligent conduct. A narrow “material contribution to risk” test is available in limited circumstances where but-for causation cannot be sensibly applied, but this exception does not apply in most cancer cases.
In delayed-cancer-diagnosis cases, the but-for test is applied in essentially the following form:
- The plaintiff identifies the date the diagnosis should have been made (here, January 2018).
- The plaintiff identifies the actual date of diagnosis (here, August 2018).
- The plaintiff must prove that, with diagnosis on the earlier date, the outcome would have been substantially better (cure, longer survival, less morbidity).
The expert evidence on what would have happened with earlier diagnosis is the foundation of the causation analysis. The relevant questions include:
- What stage was the cancer at the time the diagnosis should have been made?
- If treated at that point, what was the likelihood of cure?
- If treated at that point, what was the expected survival?
- How does that compare to the outcome that actually occurred?
In Tripp, the trial judge accepted that the cancer was already metastatic in January 2018. With distant metastases already present, the disease was incurable regardless of when the intervention occurred. The but-for test was not satisfied as to the death.
The split outcome doctrine
Tripp is also a useful illustration of the doctrinal point that a single breach can cause one harm without causing another. The same negligent conduct (the truncated colonoscopy) caused two distinct categories of consequences:
- The death from cancer: the trial judge found that this would have occurred regardless of when the diagnosis was made, because the cancer was already metastatic at the relevant time. Causation was not satisfied on this head.
- The additional pain and suffering: the trial judge found that the delay had produced additional suffering that the patient would not otherwise have experienced. Causation was satisfied on this head.
The two findings are doctrinally consistent. Causation is a question about specific harm and specific conduct, not about negligence in the abstract. A breach that does not cause one harm may still cause another. The plaintiff can recover for the harm the breach caused, even where the larger harm (the death) was not caused by the breach.
The pain-and-suffering award in Tripp is consistent with this framework. The award compensates for what the negligence actually caused (the additional suffering during the period the patient lived) without overcompensating for what it did not cause (the death from underlying disease).
The doctrinal lessons
The case stands for several propositions.
Admitted negligence does not produce automatic recovery. The defendant in Tripp admitted that the colonoscopy was negligently performed. The case still failed on the wrongful death claim because the medicine did not support but-for causation as to the death. In cancer cases, admitted negligence is often the starting point of the analysis rather than the end.
Metastasis timing is often outcome-determinative. In delayed-cancer-diagnosis cases, the question of when the cancer became metastatic is frequently the most important factual issue. Where the metastasis occurred before the missed diagnosis, the death is generally not caused by the delay. Where the metastasis occurred during the delay, the causation analysis is more favourable to the plaintiff.
Oncology causation expertise is essential. The trial judge in Tripp heard from medical oncologists on both sides who substantially agreed on the underlying biology. The dispute was on the timing of metastasis specifically. In any cancer case, expert oncology evidence on the natural history of the particular cancer (growth rates, metastasis patterns, response to treatment) is the foundation of the causation analysis.
Pain and suffering can be recovered independently. Even where the death is not caused by the breach, the additional suffering caused by delayed treatment can be a separate compensable head of damages. The award in Tripp is at the modest end of the range but reflects the reality that delays in cancer treatment produce real harm even where the death itself is inevitable.
Manitoba law and Ontario law are aligned. The substantive causation framework (Clements v Clements) is the same in both provinces. The doctrinal lessons from Tripp apply in Ontario without modification.
The cancer misdiagnosis context
Tripp v Ross fits within the broader body of content on this site addressing missed cancer diagnoses. Related content:
The cancer misdiagnosis sub-cluster covers the realistic outcomes in this area: cases where SOC is breached but causation defeats recovery (this case); cases where SOC is met (Martindale); and the broader analytical framework (Cancer Misdiagnosis in Ontario).
The causation and SOC defeat cluster
Tripp v Ross adds to the broader sub-cluster of cases on this site where the plaintiff did not succeed. The cluster now includes:
The seven cases together illustrate the realistic risk distribution in Canadian medical malpractice litigation. Tripp is at the causation end of the spectrum: liability was admitted but the cancer would have killed the patient regardless. The split award for pain and suffering is a reminder that even where the largest damages head fails, smaller damages may still be available.
The cross-province context
Tripp is the first Manitoba case in the rewritten cross-province sub-cluster, which now includes:
The cross-province cases illustrate the application of substantively similar legal frameworks in different provincial settings. The causation framework in Tripp applies in Ontario without modification, and the case is useful precedent for delayed-cancer-diagnosis claims regardless of where they are brought.
Why this case matters
For the plaintiff bar in cancer cases. Tripp is a sobering reminder of how often admitted negligence does not produce death damages in cancer cases. The intake analysis should always include a careful look at the metastasis timing question. Where the cancer was likely already metastatic at the time of the missed diagnosis, the strongest realistic outcome may be pain-and-suffering damages rather than wrongful death damages. The quantum analysis should reflect this.
For prospective clients with a possible cancer misdiagnosis claim. The relevant question on intake is not just whether there was a delay. It is whether the cancer would have been curable if the diagnosis had been made earlier. This requires a careful look at the medicine (the cancer type, the stage at diagnosis, the likelihood of cure at various stages, the natural history of the disease). A delay alone is not a viable claim. A delay that, in the specific medical circumstances, would have produced a different outcome is the relevant analytical frame.
For the defence bar. Tripp is useful precedent on the structure of cancer causation defence. The defence position was not that the surgeon’s conduct was reasonable (it was not — liability was admitted). The defence position was that the cancer was already metastatic at the relevant time and would have killed the patient regardless. The expert evidence on metastasis timing is the foundation of this defence.
For more on cancer misdiagnosis in Ontario generally, see Cancer Misdiagnosis in Ontario. For the broader framework of malpractice claims in Ontario, see Suing for Medical Malpractice in Ontario: What You Need to Know.
Decision Date: December 1, 2023
Jurisdiction: Court of King’s Bench of Manitoba
Citation: Tripp v Ross, 2023 MBKB 173 (CanLII)
Media coverage: MD ordered to pay $75K after late cancer diagnosis caused unnecessary pain, suffering before patient died — Winnipeg Free Press
Tripp v Ross: A Cancer Causation Defeat With Pain-and-Suffering Damages
A surgeon admitted he stopped a colonoscopy without finding the cancer. The trial judge held the death was inevitable but awarded damages for additional suffering.
Most failed delayed-cancer-diagnosis cases fail at the same point: not on liability, not on the medicine being a breach of the standard of care, but on causation. The plaintiff must prove on a balance of probabilities that earlier diagnosis would have changed the outcome. Where the cancer was already metastatic at the time the diagnosis was missed, the patient would have died regardless of when the diagnosis was made. The negligence may have caused additional suffering. It does not, on the legal framework, cause the death.
Tripp v Ross, 2023 MBKB 173, is a useful illustration. The case was decided in Manitoba, but the underlying causation framework (the “but-for” test articulated in Clements v Clements, 2012 SCC 32) is the same across Canadian common law jurisdictions, including Ontario. The case is also notable for its split outcome: the wrongful death claim was dismissed on causation, but the trial judge awarded $75,000 in pain-and-suffering damages for the additional suffering the delay caused during the period the patient lived.
This is a useful doctrinal reference for delayed-cancer-diagnosis cases, where the realistic outcome often depends less on the existence of negligence than on the natural history of the underlying disease.
The substantive case
Mr. Tripp was a 53-year-old electrician in Manitoba. In December 2017, he presented to his family physician with rectal bleeding and abdominal cramps. He was referred to a general surgeon, Dr. Ross, who saw him at the end of December and recommended a colonoscopy.
The colonoscopy was performed on January 12, 2018. The surgeon found and removed five polyps. The pathology report identified one of the polyps as having low-grade dysplasia, which is a recognized precursor of adenocarcinoma. The surgeon advised Mr. Tripp at follow-up that the polyps had been aggressive and recommended a return appointment in one year.
The surgeon’s admitted negligence is the heart of the case. Once he found the five polyps, he assumed those were the source of Mr. Tripp’s bleeding and did not continue the colonoscopy. Had he continued, he would have seen the tumour in the descending colon. The case proceeded to trial on causation only; liability was admitted.
Between March and August 2018, Mr. Tripp had episodic abdominal pain and rectal bleeding. He saw his family physician on August 1, who ordered blood work that revealed low hemoglobin and iron deficiency consistent with chronic blood loss. He was referred back to the surgeon, who saw him on August 10. A barium enema showed a tumour in the descending colon. A CT scan confirmed the tumour and identified enlarged regional lymph nodes.
Surgery was performed on October 9, 2018, just over nine months after the original colonoscopy. The extent of the surgery indicates how far the disease had progressed: the tumour was removed along with 40 percent of the pancreas, the spleen, and all but a foot of the lower bowel. The tumour had grown into the pancreas and spleen and could not be completely removed.
The post-operative course was difficult. Mr. Tripp underwent multiple rounds of chemotherapy. In November 2018, he was admitted to hospital for 11 days for a bowel perforation. Imaging in December 2018 raised concern for liver metastases. In January 2019, his pancreas failed, producing insulin-dependent diabetes that was difficult to control because of the steroids he required as part of his chemotherapy.
Mr. Tripp stopped working in December 2019. He died on February 20, 2022, approximately four years after the initial missed diagnosis.
The causation question
The trial focused on a single causation question: would Mr. Tripp have likely survived the cancer if it had been diagnosed in January 2018 rather than August 2018?
The answer turned on whether the cancer had already metastasized at the time the diagnosis should have been made. Colon cancer is generally treatable when the disease is local; once it has metastasized to distant organs (most commonly the liver), the prognosis becomes terminal.
Both sides called medical oncologists as causation experts. There was substantial agreement between them on the key clinical facts:
The disagreement was about when the metastasis had occurred. The trial judge accepted the evidence that Mr. Tripp’s cancer was likely already metastatic at the time the diagnosis should have been made in January 2018. On that finding, earlier diagnosis would not have changed the eventual outcome. The wrongful death claim was dismissed.
The pain-and-suffering award
The trial judge did not dismiss the case in its entirety. The medical evidence established that the delay had exacerbated Mr. Tripp’s suffering during the period he lived after the eventual diagnosis. The surgical recovery was longer and more painful than it would have been with earlier intervention. The chemotherapy regimen was more intensive. The complications (the bowel perforation, the pancreatic failure, the insulin-dependent diabetes) all reflected the more advanced state of the disease at the time of treatment.
The trial judge found that even if Mr. Tripp would have ultimately died of cancer regardless of when the diagnosis was made, the delay had caused additional suffering that he would not otherwise have experienced. The defence conceded the point in principle, with some disagreement on quantum.
The trial judge awarded $75,000 in damages for pain and suffering.
The doctrinal framework: but-for causation in cancer cases
The Canadian common-law framework for causation in negligence cases is articulated in Clements v Clements, 2012 SCC 32. The Supreme Court reaffirmed the “but-for” test as the default approach to causation: the plaintiff must prove on a balance of probabilities that the harm would not have occurred but for the defendant’s negligent conduct. A narrow “material contribution to risk” test is available in limited circumstances where but-for causation cannot be sensibly applied, but this exception does not apply in most cancer cases.
In delayed-cancer-diagnosis cases, the but-for test is applied in essentially the following form:
The expert evidence on what would have happened with earlier diagnosis is the foundation of the causation analysis. The relevant questions include:
In Tripp, the trial judge accepted that the cancer was already metastatic in January 2018. With distant metastases already present, the disease was incurable regardless of when the intervention occurred. The but-for test was not satisfied as to the death.
The split outcome doctrine
Tripp is also a useful illustration of the doctrinal point that a single breach can cause one harm without causing another. The same negligent conduct (the truncated colonoscopy) caused two distinct categories of consequences:
The two findings are doctrinally consistent. Causation is a question about specific harm and specific conduct, not about negligence in the abstract. A breach that does not cause one harm may still cause another. The plaintiff can recover for the harm the breach caused, even where the larger harm (the death) was not caused by the breach.
The pain-and-suffering award in Tripp is consistent with this framework. The award compensates for what the negligence actually caused (the additional suffering during the period the patient lived) without overcompensating for what it did not cause (the death from underlying disease).
The doctrinal lessons
The case stands for several propositions.
Admitted negligence does not produce automatic recovery. The defendant in Tripp admitted that the colonoscopy was negligently performed. The case still failed on the wrongful death claim because the medicine did not support but-for causation as to the death. In cancer cases, admitted negligence is often the starting point of the analysis rather than the end.
Metastasis timing is often outcome-determinative. In delayed-cancer-diagnosis cases, the question of when the cancer became metastatic is frequently the most important factual issue. Where the metastasis occurred before the missed diagnosis, the death is generally not caused by the delay. Where the metastasis occurred during the delay, the causation analysis is more favourable to the plaintiff.
Oncology causation expertise is essential. The trial judge in Tripp heard from medical oncologists on both sides who substantially agreed on the underlying biology. The dispute was on the timing of metastasis specifically. In any cancer case, expert oncology evidence on the natural history of the particular cancer (growth rates, metastasis patterns, response to treatment) is the foundation of the causation analysis.
Pain and suffering can be recovered independently. Even where the death is not caused by the breach, the additional suffering caused by delayed treatment can be a separate compensable head of damages. The award in Tripp is at the modest end of the range but reflects the reality that delays in cancer treatment produce real harm even where the death itself is inevitable.
Manitoba law and Ontario law are aligned. The substantive causation framework (Clements v Clements) is the same in both provinces. The doctrinal lessons from Tripp apply in Ontario without modification.
The cancer misdiagnosis context
Tripp v Ross fits within the broader body of content on this site addressing missed cancer diagnoses. Related content:
The cancer misdiagnosis sub-cluster covers the realistic outcomes in this area: cases where SOC is breached but causation defeats recovery (this case); cases where SOC is met (Martindale); and the broader analytical framework (Cancer Misdiagnosis in Ontario).
The causation and SOC defeat cluster
Tripp v Ross adds to the broader sub-cluster of cases on this site where the plaintiff did not succeed. The cluster now includes:
The seven cases together illustrate the realistic risk distribution in Canadian medical malpractice litigation. Tripp is at the causation end of the spectrum: liability was admitted but the cancer would have killed the patient regardless. The split award for pain and suffering is a reminder that even where the largest damages head fails, smaller damages may still be available.
The cross-province context
Tripp is the first Manitoba case in the rewritten cross-province sub-cluster, which now includes:
The cross-province cases illustrate the application of substantively similar legal frameworks in different provincial settings. The causation framework in Tripp applies in Ontario without modification, and the case is useful precedent for delayed-cancer-diagnosis claims regardless of where they are brought.
Why this case matters
For the plaintiff bar in cancer cases. Tripp is a sobering reminder of how often admitted negligence does not produce death damages in cancer cases. The intake analysis should always include a careful look at the metastasis timing question. Where the cancer was likely already metastatic at the time of the missed diagnosis, the strongest realistic outcome may be pain-and-suffering damages rather than wrongful death damages. The quantum analysis should reflect this.
For prospective clients with a possible cancer misdiagnosis claim. The relevant question on intake is not just whether there was a delay. It is whether the cancer would have been curable if the diagnosis had been made earlier. This requires a careful look at the medicine (the cancer type, the stage at diagnosis, the likelihood of cure at various stages, the natural history of the disease). A delay alone is not a viable claim. A delay that, in the specific medical circumstances, would have produced a different outcome is the relevant analytical frame.
For the defence bar. Tripp is useful precedent on the structure of cancer causation defence. The defence position was not that the surgeon’s conduct was reasonable (it was not — liability was admitted). The defence position was that the cancer was already metastatic at the relevant time and would have killed the patient regardless. The expert evidence on metastasis timing is the foundation of this defence.
For more on cancer misdiagnosis in Ontario generally, see Cancer Misdiagnosis in Ontario. For the broader framework of malpractice claims in Ontario, see Suing for Medical Malpractice in Ontario: What You Need to Know.
Decision Date: December 1, 2023
Jurisdiction: Court of King’s Bench of Manitoba
Citation: Tripp v Ross, 2023 MBKB 173 (CanLII)
Media coverage: MD ordered to pay $75K after late cancer diagnosis caused unnecessary pain, suffering before patient died — Winnipeg Free Press
Paul Cahill
Partner, Davidson Cahill Morrison LLP | LSO Certified Specialist in Civil Litigation
Paul represents victims of medical malpractice across Ontario, with trial experience including a $11.5M jury verdict in a birth injury case. He is recognized in Best Lawyers in Canada and serves as trial counsel to other lawyers on complex medical negligence matters.
About PaulMore on medical malpractice in Ontario.
Other articles by Paul exploring the conditions, decisions, and systems behind preventable medical harm.
Pros and Cons of Juries in Medical Malpractice Lawsuits
Paul Cahill’s June 2019 Lawyer’s Daily article on when to ask for a jury in Ontario medical malpractice cases, drawing on his trial experience and the law on jury notices and appellate deference.
O’Neill-Renouf v Ibrahim: An Obturator Nerve Injury, a Competing Edema Theory, and a Trial Victory
Paul Cahill won a trial verdict in O’Neill-Renouf v Ibrahim where Justice Baltman found a urologist negligently injured the obturator nerve during a TVT procedure.
Levac v James: Statistical Causation in an Infection Outbreak Class Action
The Court of Appeal upholds the use of epidemiological evidence to infer causation across a class of patients harmed by a physician’s IPAC failures.