The percentage of breast cancer survivors in Canada has doubled in the past 15 years, the study found

It was the information she couldn’t find Amy KirkhamAssistant Professor at the University of Toronto’s Department of Kinesiology and Physical Education (KPE), on her latest discovery.

Asked by the Canadian Women’s Heart Health Alliance to co-author a scientific statement on the state of heart health in Canada in 2020, Kirkham – whose research focuses on preventing and managing the risk of heart disease associated with breast cancer treatment – needed to Know what percentage of Canada’s female population has breast cancer.

But the last statistic she could find – one percent – was from 2007.

“Almost 15 years had passed and I could not find a recent quote on the prevalence of breast cancer survivors in Canada,” says Kirkham. “The breast cancer mortality rate had improved by 26 percent over that period, so I suspected that number was no longer accurate.”

So in cooperation with Katarzyna Jerzaka medical oncologist at Sunnybrook Odette Cancer Center and an assistant professor in the medical school of the U of T’s Temerty Faculty of Medicine, Kirkham began a new study that provides a current estimate of the prevalence of breast cancer survivors in Canada in 2022, using the annual cancer statistics reports of the Canadian Cancer Society.

The recently published study in the Journal of the National Comprehensive Cancer Networkfound that over the 15-year period from 2007 to 2021, 370,756 patients (2.1 percent of the adult female population in Canada in 2022) were diagnosed with breast cancer and 86 percent of these women would have survived breast cancer by 2022.

“This indicates that the prevalence of breast cancer survivors has doubled in the Canadian female population and that there are 2.5 times more survivors since the last estimate in 2007,” says Kirkham.

The previous estimate did not include the age group of survivors, but according to Kirkham and Jerzak’s new estimate, breast cancer survivors make up 1 percent of Canadian women in the typical age group of working and/or raising children (20 to 64 years) and 5.4 percent of older Canadian women (over 65 years).

But it’s not all good news.

Many of the treatments that have improved breast cancer mortality rates also cause short- and long-term side effects, which in turn can increase the risk of death from other causes, such as heart disease, stroke, Alzheimer’s, liver disease, and other non-fatal health outcomes.

“The leading cause of death in women with breast cancer is heart disease,” says Kirkham.

Such conditions also affect overall healthcare costs.

To demonstrate the excessive healthcare costs associated with heart disease, Kirkham and Jerzak performed an additional analysis using Canadian data on heart failure hospitalization rates and costs. They found that two percent of women diagnosed with breast cancer between 2007 and 2021 would likely have hospitalization for heart failure, which would cost a total of $66.5 million. Up to 25 percent of that cost, or $16.5 million, exceeded what it would cost women without breast cancer.

“Given the excessive health care costs, the potential for reduced contributions to the labor force, and the diminished quality of life associated with long-term side effects and the risk of excess death among breast cancer survivors, our work shows that there is a growing segment of the population that needs the services to support them recovery after breast cancer treatment,” says Kirkham.

“The goal of my research laboratory is to develop new therapies to improve the health of women who have recovered from breast cancer.”