The percentage of Canadian women who have survived breast cancer has doubled in the past 15 years, according to a new analysis from the University of Toronto, reflecting the tremendous progress made in the treatment of this disease in recent years.
Toronto researchers indicate in the Journal of the National Comprehensive Cancer Network that approximately 371,000 patients were diagnosed with breast cancer between 2007 and 2022 – or 2.1% of the total number of Canadian adults in 2022 – and 86% of them were still alive this year.
This would mean that there are now 2.5 times more survivors than when the last measurement was made in 2007, researcher Amy Kirkham said in a press release.
We owe this improvement in particular to the development of personalized medicine, commented Professor Alain Nepveu, who is, among other things, a researcher at the Rosalind and Morris Goodman Cancer Institute of McGill University.
“In the past, everyone was treated the same,” he said. The tumor is removed, then the classic treatment is radiotherapy and chemotherapy. But with the advent of something called gene expression, we are able to determine gene expression profiles in breast tumors. We are able to predict who is at risk and who is not. »
Such an approach makes it possible to avoid unnecessary treatments for around a third of patients, added Professor Nepveu, which represents “enormous progress” since it allows these patients to escape the undesirable side effects of these treatments, such as cardiomyopathies.
The Toronto analysis also found that 2% of women diagnosed with breast cancer between 2007 and 2021 would likely be hospitalized for heart failure ― resulting in enormous costs beyond the impact on their health. and potentially useless for the system.
To the list of progress made in the treatment of breast cancer, continues Professor Nepveu, we must add an improvement in radiotherapy which makes it possible to target the tumor with unparalleled precision; neoadjuvant treatments that allow the tumor to melt before surgery; and immunotherapy which sends the immune system to attack and destroy disease.
“When I started 35 years ago, you never heard of side effects,” he said. Today, we have a population of survivors who complain about long-term side effects. And that is progress. »
And even in cases where full recovery is unlikely, he says, going from a life expectancy of three years to, say, 15 years is a huge improvement.
Breast cancer survivors represent 1% of Canadian women aged 20 to 64, and 5.4% of Canadian women aged 65 and over, according to the Toronto analysis.