Women living in communities with early breast cancer screenings before the age of 50 have a better chance of surviving, a new study shows.
Published in the Journal of Clinical Oncology, a team of researchers from The Ottawa Hospital and the University of Ottawa found that people who live in provinces and territories with breast cancer screenings for women aged 40 to 49 had a lower risk of death.
Using data from the Canadian Cancer Registry at Statistics Canada, researchers looked at 50,921 women aged 40 to 59 who were diagnosed with breast cancer between 2002 and 2007.
The data shows cancer rates were higher for women aged 50 to 59 in provinces and territories where early screenings are not available.
When screening took place earlier, the chance of surviving breast cancer 10 years after a diagnosis was 84.8 per cent. For provinces and territories where early detection was not available, a woman's survival rate after 10 years was 82.9 per cent.
Dr. Jean Seely, a radiology professor at the University of Ottawa and the head of breast imaging at The Ottawa Hospital, said the most challenging part of her job is knowing practices to diagnose breast cancer early are not being used.
"When I see women many of them tell me, 'I asked my family physician if I could get screened and they refused.' And then three years later, they're here presenting with a big lump," Dr. Seely told CTVNews.ca in an interview. "I find that very, very difficult to be able to accept and this happens so regularly."
BARRIERS TO SCREENING
Many communities across Canada do not have programs aimed at routine early breast cancer screenings.
The Northwest Territories, B.C., Alberta, N.S. and P.E.I. have early mammogram screenings, whereas Yukon, Manitoba, Saskatchewan, Ontario, Quebec, N.B., and Newfoundland and Labrador do not.
Nunavut was not included in the study because it does not have a screening program in place.
Seely says physicians are guided by the Canadian Task Force on Preventative Health Care, which says if a woman chooses to be screened she is entitled to that.
"But it's misinterpreted by many physicians who read (that) the Canadian Task Force does not recommend screening in their 40s," she said. "That's based on very old data, but a lot of family physicians just follow that and say, 'Well, you're not allowed.'"
Not only are some women discouraged from doing early testing, screenings in many provinces are only accessible through a doctor.
Across Canada, many people are unable to get a family doctor due to a shortage of workers.
"If you don't have access to a family physician you can't get a screening mammogram in your 40s," Seely said. "Whereas if you're in your 50s and 60s and 70s, you can self-refer to a screening program."
Seely is pushing to lower the age of self-referral for breast cancer screening – rules that disproportionately affect marginalized women and new immigrants to Canada.
"We really do a poor job of getting them (screened) and they have a later stage diagnosis than even white women," Seely said.
Other reasons why screening for people in their 40s is debated include the risk of false positives, benign biopsies and overdiagnosis.
However, Seely says hiring additional radiologist technicians and allowing for earlier breast cancer screenings would be more cost-effective for the health-care system than having someone go through cancer treatment.
"We know that when we treat a more advanced breast cancer, they're more likely to need chemotherapy, more likely to need to have a full removal of the breast (so) the cost to our health-care system in terms of treating advanced breast cancer is huge," she said. "We looked at the cost of treating a patient with metastatic breast cancer, one patient can cost over $500,000."
AMONG THE LEADING CAUSES OF DEATH
Breast cancer is among the leading causes of death for women in their 40s and 50s in Canada.
In 2020, it accounted for 10.5 per cent of all deaths of women in their 40s, second to only accidental deaths at 11.5 per cent, the study reads. Breast cancer is the leading cause of death for women in their 50s (10.4 per cent) in 2020, greater than heart disease (9.3 per cent).
Not only is breast cancer often aggressive, but it can also present itself in women without any history of cancer, Seely said. About 80 per cent of women who get breast cancer have no family history of it, she said.
This is why Seely is an advocate for early measures to prevent more women from developing breast cancer at a later stage.
"Out of 100 women diagnosed with breast cancer in their 40s, an extra two and a half women are living longer because they lived in a province that offered screening," she said.
The women included in the study were not necessarily screened, Seely said.
"It's very likely we have underestimated the benefit of screening because even in the provinces that screened the most, there was a 44 per cent participation in screening, so less than half of women actually participated," she said. "So if we actually brought it up to the target for Canada, which is 70 per cent, we are almost certainly going to see even more benefit."
This could mean more women living longer and surviving breast cancer.
"The study really consolidates the scientific evidence that shows screening does impact survival," Seely said. "For the first time, probably in 15 years, I actually believe that we are going to make this change happen in Canada. I'm very optimistic."
