When Dr. Anil Kapoor, a respected urologist and head of transplants at St. Joseph’s Healthcare in Hamilton, Ontario, was diagnosed with stage four colon cancer in January 2023, the outlook was cautiously optimistic. Thanks to decades of advancements in oncology, his medical team and family believed treatment would grant him valuable time, perhaps even years.
But just weeks later, the 58-year-old was gone.
Not because of the cancer.
But because of the treatment itself.
Dr. Kapoor suffered a fatal reaction to 5-Fluorouracil (5-FU) which is a chemotherapy drug that has been widely used since the 1970s to treat colorectal, breast, stomach, and cervical cancers. While it is effective for many, for a subset of patients with certain genetic variants, it can be highly toxic, even deadly.
“One thing that strikes home is these patients are dying because of
their treatment, … and not necessarily dying because the cancer has
progressed.”
Dr. Steven Offer, Mayo Clinic cancer researcher
A Promising Treatment Gone Wrong
Dr. Kapoor underwent genetic pre-screening before beginning chemotherapy, a precaution intended to identify whether he carried any of the known variants associated with severe 5-FU toxicity. The results gave him the green light to proceed.
But just days after his first dose, he became violently ill, suffering from relentless vomiting, inflammation of the throat and digestive tract, and severe diarrhea. His condition deteriorated rapidly. Despite urgent care, Dr. Kapoor died within three weeks.
It was only after his death that full genome sequencing revealed the real cause: he carried a rare genetic variant that made 5-FU toxic to his system, a variant not included in the standard test panel.
The Hidden Bias in Pre-Screening
Across Canada, genetic pre-screening for 5-FU varies by province and often focuses on just four common variants primarily identified through studies involving white, Western European populations. This narrow approach leaves millions of Canadians from diverse ethnic backgrounds vulnerable to undetected risks.
In Dr. Kapoor’s case, his South Asian ancestry may have played a role. His brothers, both physicians, say they were shocked to discover how underrepresented non-white populations are in genetic research tied to cancer drug responses. As Ontario Health’s own clinician guidance noted earlier this year, current genetic tests “largely favour a Caucasian population.”
Dr. Kapoor’s death is a painful example of what happens when the diversity of real-world patients isn’t reflected in the research that guides medical decisions.
The Human Cost of Data Inequity
Today, 84% of the world’s population is underrepresented in the genetic data used to design drugs, build diagnostics, and train AI for healthcare. That gap leads to misdiagnoses, adverse reactions, and too often, avoidable deaths.
“I think the more important thing is that nobody’s informing the
patients… So as you and I are sitting here right now, there are people
sitting in the hospital being given this drug, who are not of northern
and western European ethnicity, and they are completely vulnerable.”
Dr. Scott Kapoor, brother of Anil Kapoor
At PAICON, we call this
the Remaining84 Problem, and it drives everything we do.
We are building an inclusive, genetically diverse data lake for cancer
AI.
We are developing models that work for everyone, not just the selected
few.
Learn more about Remaining84
Don’t Just Read. React. Act. Change Something.
If this story moved you, do something with that feeling:
Share it: Raise awareness about the risks of outdated, non-inclusive
healthcare systems.
Question it: Ask your care team: “Is this test or treatment built
for me?”
Support change: Support initiatives that demand data diversity and
equity in medicine.
Join the conversation: Post your thoughts with #Remaining84 and
emphasize the need for inclusive innovation.
Personalized medicine is only personal if it includes you.
Let’s stop building systems that leave people out.
Speak up. Save lives. Shape the future.
References
Marchitelli, R., & Blair, J. (2023, Nov 27). This commonly prescribed cancer drug was supposed to help save this doctor’s life. Instead, it killed him. CBC News. Retrieved from https://www.cbc.ca/news/canada/toronto/cancer-drug-5fu-genetic-variant-testing-1.7039145
