Black women are at greater risk of dying from early-stage breast cancer when compared with women of other races and ethnicities, according to a study published Tuesday by researchers at Women’s College Hospital.
Experts looked at American data and found that seven years after being diagnosed with small tumours that were 2 centimetres or less, about 95 per cent of women were still alive.
But figures varied between patients, largely depending on ethnicity and race, explains Dr. Steven Narod, director of the Familial Breast Cancer Research Unit at Women’s College Research Institute and Canada Research Chair in Breast Cancer.
For instance, the probability of a woman dying was significantly higher for black women at nine per cent, compared with five per cent for white and Hispanic women and two per cent for Asian women. Among Asian women, there was a three per cent risk of death for Chinese women, two per cent for Japanese and four per cent for Indian and Pakistani women.
According to the study, which was published in the Journal of the American Medical Association, researchers looked at medical records of 373,563 American women diagnosed with invasive breast cancer from 2004 to 2011. When they looked at survival rates seven years after diagnosis, they noticed wide disparities along racial and ethnic lines. Biological differences in the tumours explain some of these findings. Other factors may include lifestyle, diet and genetics.
If such a study was done in Canada, Narod believes “we would see similar variations.”
“I would dearly love to study the Canadian women, but it’s just not that simple,” Narod told the Toronto Star, saying looser regulations in the U.S. make it much easier for researchers to access American data than Canadian figures.
Dr. Javaid Iqbal, the study’s lead author, says more research is needed to understand whether these disparities are linked to differences in intrinsic genetics, environmental factors, lifestyle or diet.
“Adherence to breast cancer awareness and screening is paramount,” Iqbal told the Star. “And, women should understand their individualized risk of breast cancer based on their family history, reproductive history and ethnicity.
“And on the clinicians’ part, it’s important to avoid treatment delays in ethnic groups that are at higher risk of survival disparity, such as black women.”