Even with equivalent treatments in women with hormone receptor-positive, HER2-negative breast cancer, black women had significantly higher breast cancer recurrence and increased overall mortality compared to white women in a large phase III clinical trial, TAILORx, according to data presented at the 2018 San Antonio Breast Cancer Symposium, held Dec. 4-8, News Medical says.

"Our findings are consistent with prior studies indicating that black women with hormone-receptor positive, HER2-negative breast cancer have worse prognoses than women of other racial and ethnic backgrounds, even when they have access to the same contemporary cancer care," said Kathy Albain, MD, Huizenga Family Endowed Chair in Oncology Research and professor of medicine at Loyola University Chicago Stritch School of Medicine and director of the Breast and Thoracic Oncology Programs at the Cardinal Bernardin Cancer Center of Loyola Medicine in Maywood, Illinois. "This suggests that additional research is required to determine the basis for these racial disparities and also highlights the need to enhance accrual of minority populations in cancer clinical trials."

Albain and colleagues analyzed the association between clinical outcomes and race in participants from the TAILORx trial, which evaluated more than 10,000 women with the most common type of early breast cancer (hormone receptor-positive, HER2-negative, axillary lymph node-negative). Findings released from the TAILORx study in June 2018 showed no benefit from chemotherapy for 70 percent of the women in the trial. It found that treatment to prevent the cancer from returning with chemotherapy and hormone therapy, following surgery, is not more beneficial than hormone therapy alone in patients with a low or intermediate recurrence score.

Following enrollment in the TAILORx trial, patients' tumors were analyzed using the 21-gene Oncotype DX recurrence score (RS; on a scale of 0-100) which predicts cancer recurrence. Patients with low risk (RS score of 0-10) were treated with hormone therapy alone, while patients with high risk (RS score 26 and above) were treated with hormone therapy and chemotherapy. Patients with an intermediate risk of recurrence (RS score of 11-25)--the primary study group--were randomized to receive hormone therapy and chemotherapy or hormone therapy alone.

Of the 9,719 breast cancer patients able to be evaluated, 8,189 (84 percent) were white, 693 (7 percent) were black, 405 (4 percent) were Asian, and 432 (4 percent) were of other or unknown race. In terms of ethnicity, 7,635 (79 percent) were non-Hispanic, 889 (9 percent) were Hispanic, and 1,195 (12 percent) were of unknown ethnicity. The trial showed no significant difference in RS distribution or mean RS between white and black participants.