Disease-free, overall survival inferior for black women with HR-positive breast cancer

"Black women had a higher risk for disease recurrence and inferior survival compared with women of other races," said Joseph A. Sparano, M.D., professor of medicine and women's health at Albert Einstein Medical College of Medicine and associate chairman of the Department of Oncology at Montefiore Medical Center in Bronx, N.Y.

"The worse outcome was seen only in those with HR-positive, HER-2-negative breast cancer, which is the most common type of breast cancer" he added.

Previous research has shown that black women have worse outcomes in operable breast cancer, likely explained by their higher incidence of more advanced-stage disease, more aggressive triple-negative disease, disparities in medical care, and comorbidities.

"When we controlled for these other factors to the extent possible, black race was still associated with a worse outcome, but only in HR-positive disease -- this was a new and surprising finding," said Sparano.

The researchers evaluated survival outcomes in 4,817 women (405 were black) with stage 1 to 3 axillary lymph node-positive or high-risk node-negative breast cancer who had undergone surgery. The women were part of the Eastern Cooperative Oncology Group and Breast Cancer Intergroup trial E1199; they received doxorubicin and taxane-containing chemotherapy plus standard hormonal therapy.

"We found that black patients exhibited similar adherence to the chemotherapy and hormonal therapy, and they didn't do worse if they had other breast cancer subtypes. This indicates that black women with HR-positive breast cancer are more prone to have disease recurrence despite state of the art medical care," said Sparano.

The researchers are planning additional studies to evaluate whether these findings can be attributed to differences in black women's ability to metabolize hormonal therapies.