Differences in insurance coverage contribute to disparities in breast cancer mortality risk, with black women having up to a one-third higher risk of death from breast cancer than white women, according to a study published online October 16 in the Journal of Clinical Oncology.
Researchers from the American Cancer Society (ACS), Emory University in Atlanta, and the Dana-Farber Cancer Institute in Boston examined the effect of a variety of factors -- including demographics, comorbidities, insurance, tumor characteristics, and treatment -- on the breast cancer mortality risk for black and white women. Lead author Ahmedin Jemal, PhD, and colleagues used National Cancer Database data from more than 550,000 women diagnosed with early-stage breast cancer.
Compared with white women, black women were more likely to be uninsured or have Medicaid insurance (22.7% versus 8.4%) and were more likely to have tumors that were larger, higher grade, and hormone-receptor negative, the researchers found.
Among those with hormone receptor-negative disease, black women had a 49.5% excess risk of death compared with white women. This risk decreased when the researchers adjusted for various factors, but the factors combined accounted for 63.6% of the total excess risk of death in black women (insurance, 34.1%; tumor characteristics, 22%; comorbidities, 3.8%; and treatment, 3.6%).
Among those with hormone receptor-positive tumors, the risk of death in black women was twice that of white women. Again, this excess risk among black patients with these tumors decreased when they were matched with white patients by various factors, but these factors together accounted for 75% of the total excess risk of death in black patients (insurance, 37%; tumor characteristics 23.2%; comorbidities, 11.3%; and treatment, 4.8%).
"We found that differences in insurance explained one-third of the total excess risk of death in nonelderly black women compared to white women diagnosed with early-stage breast cancer, while differences in tumor characteristics explained approximately one-fifth of the excess risk," Jemal and colleagues wrote. "Equalization of access to care in nonelderly black women could substantially reduce ethnic/racial disparities in overall mortality of women diagnosed with breast cancer."
