Your chances of being diagnosed with early breast cancer, as well as surviving it, vary significantly depending on your race and ethnicity, according to a study.
“It had been assumed lately that we could explain the differences in outcome by access to care,” said Steven Narod, M.D., professor of public health at the University of Toronto, and lead author. This assumption is likely because in earlier studies, experts have found some ethnic groups have better access to care.
But that’s only part of the story. Dr. Narod and his team discovered racially based biological differences, such as the spread of cancer to the lymph nodes or having an aggressive type of breast cancer known as triple-negative, are responsible for much of the disparity. “Ethnicity is just as likely to predict who will live and who will die from early breast cancer as other factors, like the cancer’s appearance and treatment,” he said.
In this study, nearly 374,000 women who were diagnosed with invasive breast cancer between 2004 and 2011 were followed for about three years. Researchers divided the women into eight racial or ethnic groups and looked at the types of tumors, how aggressive the tumors were and whether they had spread. The results: Japanese women were more likely to be diagnosed at stage 1 than white women, with 56 percent of Japanese women finding out they had cancer early, compared to 51 percent of white women. But black women and South Asian (Asian Indian, Pakistani) women lagged far behind, with only 37 percent and 40 percent respectively receiving an early diagnosis.
When researchers calculated the seven-year death risk, black women topped the list, with a 6 percent death rate. South Asian women had the lowest, at less than 2 percent. Black women were also nearly twice as likely as white women to die following the diagnosis of small tumors, according to the study.
In an editorial that accompanied the study, Bobby Daly, M.D., a hematology-oncology fellow at the University of Chicago Medical Center, pointed out that the new research “makes significant strides in explaining the well-known racial disparities in breast cancer. It makes strides in showing how the difference in survival may reflect intrinsic differences in the biology of the tumor.”
None of the researchers are suggesting that access to care isn’t a factor in breast cancer survival. There still need to be improvements on that front, Dr. Daly noted, especially when it comes to treating women according to established guidelines and avoiding treatment delays.
Women also need to be proactive. Regardless of their race or ethnicity, they should know their family health history, be aware of other risk factors they may have and stay on top of appropriate screenings and mammograms.
Finally, minority women must be included in larger numbers in future research, said the authors of the editorial.