Black women less likely to survive breast cancer, study shows

The breast cancer survival rate of African-American women is significantly shorter than it is for white women, according to research published Wednesday in the Journal of the American Medical Association. That's because black women often have more advanced cases of cancer when they first seek treatment, and they also tend to have more health problems than white women in general.

In a study of Medicare patients aged 65 and older, black women were nearly 13 percent less likely to have survived five years after receiving a breast cancer diagnosis than were white women of the same age, according to Dr. Jeffrey Silber of Children's Hospital of Philadelphia, who co-authored the study.

“They’re coming in with worse diseases, but they’re coming in with other health problems, too,” Silber told Al Jazeera America. “At diagnosis, there’s already a huge disparity in the disease and in the condition of the patient.”

The results point to the fact that while white women tend to have higher overall incidence of breast cancer, black women more often die from it, probably because they're less likely than white women to get screened and they receive lower-quality medical care in general, according to the American Cancer Society.

Silber and his colleagues used a database of Medicare patients to analyze the cases of 7,375 black women diagnosed with breast cancer between 1991 and 2005, selecting an equal number of white women out of 107,273 patients who matched the black women exactly in terms of age, location and date of breast cancer diagnosis.

When comparing the women in terms of those demographics, just 55.9 percent of the of the black women had survived five years later, compared to 68.8 percent of the white women, adding up to a three-year survival disparity, according to the study.

The researchers attribute this large discrepancy to the fact that the black women had more health problems to begin with—some 26 percent of the black women also had diabetes at the time of their breast cancer diagnosis, compared to 15.3 percent of the white women.

The black women also tended to have larger tumors and more advanced cases of cancer when they went in for diagnosis, according to Dr. Silber.

For example, 21.6 percent of the black women had tumors that were larger than 4 centimeters when they saw a doctor, versus just 11.6 percent of the white women.

When the researchers compared black and white women’s cases who had the same size and severity of breast cancer tumors and the same additional health problems at diagnoses, the difference in survival rates was only 4.4 percent lower for black women than it was for white women. And when the women had also received the same kinds of breast cancer treatments, the difference in survival rates shrank to just 3.6 percent.

In other words, the black women with breast cancer fared worse than their white counterparts because they were more likely to have additional health problems such as diabetes or heart failure in addition to the cancer. When the black and white women in the study had the same severity of cancer and the same treatment, the disparity in their survival rates fell. 

The difference in treatments received only accounted for 0.89 percent of the overall 12.9 percent survival difference between the black and white women.

A lack of health insurance isn’t the cause, Dr. Silber points out, but rather discrepancy in seeking medical care overall.

“These are Medicare patients who all had insurance,” he said. “Blacks had significantly lower rates of preventative health actions” like colon cancer screenings and annual checkups.

The researchers found that some 12.6 percent of black women received no breast cancer treatment at all, versus just 5.9 percent of whites. Black women also waited longer to seek treatment for breast cancer after diagnosis--an average of 29.2 days, as opposed to an average wait of 22.5 days among the white women.

“If we’re really going to improve the survival problem, we have to solve the primary care problem,” said Silber. “It’s the whole system surrounding how patients relate to their doctors.”

Dr. Jeanne Mandelblatt, associate director for population sciences with the Georgetown Lombardi Comprehensive Cancer Center, co-wrote an editorial that ran alongside Wednesday's JAMA study pointing to the “inherent limitations of the data.”

Because the study analyzed breast cancer cases from a database of Medicare patients, “those results don’t tell us anything about what contributes to the disparities in women under 65," she told Al Jazeera in a telephone interview.

She pointed to other modeling research studies looking at the overall U.S. population, across the age spectrum, in which she's found that breast cancer screenings accounted for about 4 to 7 percent of the black-white differences in mortality, and breast cancer treatments accounted for about 11 to 14 percent of the black-white differences in mortality.

However, many of the reasons for the differences between black and white women's breast cancer mortality rates are unexplained, according to Dr. Mandelblatt.

She stressed that women shouldn’t feel like pre-existing health conditions are more important to their survival than breast cancer treatment, or that they shouldn’t get treatment. "Women need to understand that good quality, complete treatment is critical for survival," Dr. Mandelblatt said.