SHIFT: 'Imagine women waiting for years while their cancer grows just because of some rule'

A new study has identified flaws in data used to develop breast screening criteria, a mistake that experts say may have caused the deaths of more than 400 Canadian women annually.

Lisa Machado 5 minute read November 29, 2021

Experts say mistakes made in 1980s breast screening trials have put women at risk for decades. GETTY

“Oh, we don’t do that yearly anymore.”

This was the breezy response from my family doctor to my question about getting a Pap test. I was in for an annual checkup that had for years included a blood pressure check, blood tests to monitor things like cholesterol levels and diabetes risk, as well as a Pap test and a breast exam.

“Every three years is now the standard,” he said about the Pap test, as he opened the examination room door to leave. “Oh, and you don’t really need to be doing the breast self-exam.”

He went on to explain how experts had determined that doing breast self-exams were not as helpful as originally thought because instead it was believed they often resulted in false positives, unnecessary tests and biopsies and caused needless anxiety.

He noted another recommendation for the frequency of Pap tests — unless a woman was at risk for cervical cancer —“Do you have cervical cancer in your family?” he interrupted himself to ask. When I shook my head, he continued, “Yes, well then, with no risk factors, there is no evidence that routine screening changes outcomes.”

“Checking just doesn’t change how things turn out,” he said, as he walked down the hall with a wave.


I am all for reducing anxiety, especially since I tend to be a glass-half-empty kind of person when I have a health concern — what with my questionable genes and current diagnostic track record. A headache must be a brain tumour, a weird-looking mole is melanoma and what feels like a urinary tract infection, well, has to be bladder cancer, of course.

So you might think that telling me I no longer have to worry about checking my breasts for lumps and bumps would be, well, a bit liberating.

Except for that time a friend found what felt like a small nodule under her arm — a discovery that she said made her doctor’s eyes widen as he filled out a requisition for a mammogram. It turned out okay, but if it were bad news, at least it would have been caught.

Or the time last year, when my dog’s vet — in the second year of no Pap test — sought medical advice at a walk-in clinic for a urinary tract infection, and ended up with a random Pap test as suggested by the young doctor. Two days later, he emailed her a referral to a gynecologist to investigate the abnormal results. The lucky diagnosis was pre-cancerous proof of the possibility of an aggressive form of cervical cancer.

So while I can understand the importance of guidelines that caution against over-screening and over-testing, both from a patient impact point of view and from a cost perspective, I can also see things from another critical perspective — that of the person who potentially could be a patient, either sooner or later. And what about the  devastating possibility that the experts and policy-makers who develop screening criteria don’t have it quite right. What if they are wrong?

After all, many of us — including healthcare professionals — are only as vigilant as the guidelines.

This week, a group of Canadian and American researchers representingToronto’s Sunnybrook Research Institute, The Ottawa Hospital, the University of Alberta and Harvard, published a paper outlining deadly flaws in the 1980s data used to shape Canada’s breast screening guidelines. The data, from the Canadian National Breast Screening Study (CNBSS), was based on two Canadian trials and showed that mammograms for women in their 40s did not decrease death rates any more than physical exams. But in fact, seven other trials from around the world concluded the opposite. Worryingly, the flawed findings went on to inform the foundational criteria on screening for women recommended by the Canadian Task Force on Preventive Care.

The response from healthcare experts on the new paper has been scathing.

“It is heartbreaking to know that women’s lives have been lost due to the influence of these flawed studies on screening policies,” said Dr. Paula Gordon, a radiology researcher and clinical professor in British Columbia. Dr. Jean Seely, a professor of radiology at the University of Ottawa, and head of breast imaging at The Ottawa Hospital, told CBC News that given the findings, women aged 40 and up should be getting regular mammograms.

“I was astonished. I did not expect to find such clear, clear evidence of what was going on,” said Seely, who was one of the authors of the new study. “Then I think my next reaction was anger. How could this have been allowed?”

And perhaps the most damning conclusion came from lead author Dr. Martin Yaffe of the Sunnybrook Research Institute who said that the “the study’s influence on policy may have contributed to the avoidable deaths of more than 400 Canadian women annually.”

And while the original study certainly has its supporters — Dr. Karsten Jørgensen, acting director of the Nordic Cochrane Centre, which reviews medical trials told the CBC that the CNBSS trial was one of the most “well-documented and well-run” compared to a number of other breast cancer screening trials — the paper’s researchers have escalated their concerns to both the University of Toronto and the Canadian Medical Journal prompting a review.

So far, according to the CBC, there has been no word from the Canadian Task Force on Preventive Health Care on whether or not it would consider changing current guidelines on breast cancer screening to include women in their 40s.

It’s just another reminder that no matter how much we want to depend on our healthcare system for support and care that is fulsome, timely and life-saving, it — like this study — is imperfect. And the cost of that is lives. Our lives.

None of us want to be caught up in a vortex of tests and risky diagnostic procedures that are unnecessary. Even my dog’s vet, who, because of sheer luck got a diagnosis before things became deadly, would say that the tests aren’t the issue. When she tells the story she always ends it the same way.

“Imagine all the women who are waiting for years while their cancer grows because of some rule,” she says. “Imagine.”

Lisa Machado is the executive producer of Healthing. She can be reached at or @iamlisamachado.

This story appeared in the Healthing Weekender. Click here to subscribe.

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