Black women have lower breast cancer survival rates. Why?
Doctors and cancer researchers have known for decades that black women’s likelihood of surviving breast cancer is strikingly lower than white women’s likelihood. But they weren’t sure if the reason could be traced to characteristics of the disease at the time of diagnosis – or to treatment differences. Now they have some answers.
New research indicates that breast cancer may be killing black woman at a higher rate largely because their cancer is often more advanced when they first seek medical care and because they have poorer health at the time of diagnosis. There were treatment differences, the research found, but not ones that had a large impact on overall survival.
The study, published in the Journal of the American Medical Association, looked at women 65 and older who were covered by Medicare. Researchers compared 7,375 black women who were diagnosed with breast cancer between 1991 and 2005 to 7,375 white women, divided into three groups. One group was matched on demographics, one on presentation (demographic variables, tumor characteristics and coexisting health problems) and the other on type of treatment.
Researchers found that white women with breast cancer lived, on average, three years longer than black women. Nearly 70 percent of white women lived at least five years after diagnosis and less than 56 percent of black woman were still alive five years later.
Black women were less likely to receive a diagnosis at the early stages of cancer, when it is most curable, researchers found. Further, 20 percent of the black women studied received a diagnosis of Stage III or IV disease, when the cancer is less likely to be cured. Only 11.4 percent of white women had a late-stage diagnosis.
“Now we need to figure out why they are presenting later,” said Laura Kruper, M.D., director of the Rita Cooper Finkel and J. William Finkel Women’s Health Center and head of breast surgery at City of Hope, in an interview with HealthDay. “It’s not just about the screening. It’s about access, and it’s due to education and socioeconomic factors.”
Many patients with advanced cancer didn’t even realize they were supposed to get a mammogram every year, Kruper said. And, as she noted in an interview with NBC News, other factors, such as cultural differences, matter too.
“I do have women who come in and say, ‘God is going to heal me,” she said.
In the study, researchers also found that the black women come in sicker, with more advanced disease and with more chronic conditions. They found that 26 percent of the black patients already had diabetes when they were told they had breast cancer. Only 15.3 percent of white women matched for age, year of cancer diagnosis and area of residence had diabetes.
Kimlin Tam Ashing, Ph.D., director of the Center of Community Alliance for Research & Education at City of Hope, told the Los Angeles Times that the study underscored the far-reaching effects of racial disparities in health care.
"The burden diabetes brings to the cancer experience is horrendous," Ashing said. The poorer health experienced by black women before breast cancer could be traced in part to basic factors such as poor nutrition and less exercise.
Ultimately, the researchers concluded, black women overall could gain two additional years of life if their breast cancer was detected earlier and if their health were better.