Black women face up to 70 per cent higher breast cancer mortality, study finds

A radiologist uses a magnifying glass to check mammograms for breast cancer.

A new study has found that Black women face up to 70 per cent higher death rates from breast cancer compared to white women, prompting medical experts and advocates to call for increased risk-based screening in Canada.

The study analyzed breast cancer incidence, age at diagnosis, stage, subtype, and death in Canadian Black women by different ancestry groups.

It found that Black women of Caribbean origins had a 70 per cent higher death rate than white women at ages 40 to 49 and a 42 per per cent higher death rate between ages 50 to 59. The study also found that Black women died of breast cancer younger than white women: the average age of death for Black women was 53 to 66, compared to 71 for white women.

“Breast cancer is not a single disease, it is many different histologies, many different molecular subtypes with different trajectories and outcomes, and that certainly varies by race,” Dr. Anna Wilkinson, a family physician and general practitioner-oncologist at the Ottawa Hospital who led the study, told CTVNews.ca in an interview.

The study also found that Black women are diagnosed younger than white women, with more than 50 per cent of breast cancer cases in Black women diagnosed before the age of 50, compared to about 14 per cent in white women.

Black women are also more likely to be diagnosed with more aggressive subtypes, like triple-negative breast cancer, that don’t respond to certain treatment, the researchers found.

They face up to 21 per cent higher rates of triple-negative breast cancer, compared to about 9.9 per cent for white women.

Additionally, Black women are more often diagnosed at stage II or higher: 39 per cent of cases were diagnosed at Stage I among Black women, compared to 50 per cent among white women.

“We’re seeing some worrisome data telling us that there are disparities in breast cancer for Black women in Canada,” Dr. Aisha Lofters, a clinician scientist and a family physician at Women’s College Hospital in Toronto who was also part of the study, told CTVNews.ca.

“We want to get to the point where breast cancer screening is risk-based, based on you as an individual and your personal risk factors, and I think this study highlights that might include your ancestry as well.”

Risk-based approach

Breast cancer screening programs are largely targeted to asymptomatic women at average risk of developing breast cancer between the ages of 40 and 50, depending on the province or territory.

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But each woman’s risk of developing breast cancer is different, and recent Canadian studies have shown rising diagnoses in young women, higher rates of triple-negative breast cancer in young women, and differing impacts on ethnic and racialized groups. Therefore, screening based on age and with the same type of imaging and frequency may not be equally effective for all women, Dr. Wilkinson and Dr. Lofters said.

This is why researchers say increased risk-based screening strategies that consider multiple risk factors are needed in Canada to address breast cancer trends.

“When you talk about risk stratification for screening, one of the things to think about in women with high rates of triple-negative breast cancers is that annual screening might make more sense for those women in terms of finding things early,” Dr. Wilkinson said.

“Triple-negative breast cancer tends to grow faster, and when you’re suggesting screening every two years, which is what we have, in the case of triple-negative cancer, because it grows quicker, you’re not always going to find it at an early stage.”

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Canadian Breast Cancer Network is also advocating for increased risk-based screening in Canada.

They are recommending that a national guideline be established to define average, elevated and high-risk levels of breast cancer and outline the appropriate imaging and screening frequency for each, for all provinces and territories to follow.

“The idea is that after someone finds out if their average, elevated or high risk, then there’s different pathways that they could take. Rather than everyone getting the same modality and frequency, it’s much more personalized,” Bukun Adegbembo, director of operations at Canadian Breast Cancer Network, told CTVNews.ca.

“The current model is missing people because it’s only focused on one perspective of what increases someone’s risk of being diagnosed with breast cancer. Age is one of those factors, but it’s only one (…) We have to be ahead of what we need and not just reacting to it. We need to be ahead of the curve.”

Every province and territory in Canada has their own way of defining each risk and providing corresponding screening to it.

Some provinces and territories have high-risk organized programs for breast cancer and hereditary cancers, like in Ontario, Nova Scotia, B.C. and Manitoba, other jurisdictions do not.

In most cases, women must self-advocate and consult with a health-care provider if they believe they are high-risk and may be recommended genetic testing, genetic counselling and alternative screening methods.

As a result, screening might vary by location, but according to Adegbembo, this is not equitable.

“Regardless of where someone lives in Canada, it should not impact the type of care that they have,” she said.

“We need to have those national standards so that everyone’s looking towards the same goal.”

Age-based discrimination

However, increasing risk-based screening across Canada is one part of addressing recent trends in breast cancer, Dr. Lofters said.

Other barriers include shortage of family doctors in Canada, access to screening, and younger women having their symptoms dismissed, which can lead to later-stage diagnosis.

“We often have a very specific picture in our mind of a woman with breast cancer, and that picture is often somebody who is maybe in their 60s and is white,” she said.

“We’re seeing several cancers that now are shifting to being diagnosed at younger ages, and the reason is unclear, but it is happening, and breast cancer is one of those (…) We see from this study that Black women do tend to have breast cancer at younger ages, so we as health-care providers really need to be vigilant and take people’s concerns seriously.”