An analysis of race and ethnicity data from the TAILORx clinical trial was presented at the 2018 San Antonio Breast Cancer Symposium. The new study confirms that women of all races and ethnicities can safely follow the TAILORx findings. However, the study also found that after nine years of follow-up, 83.1 percent of white women were alive and cancer-free, compared to 78.9 percent of black women. It found that the type and duration of chemotherapy and hormone therapy treatments were similar among black and white women and other races as well as between Hispanic and non-Hispanic women. Pathologic characteristics of the tumors were no different as well.
"The study adds to an emerging body of evidence suggesting there are biological factors contributing to racial disparities in breast cancer outcomes," said lead author Kathy S. 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.
The most common type of early breast cancer is hormone receptor-positive, HER2-negative breast cancer that has not spread to lymph nodes. The 'recurrence score' is a measure of how likely cancer will recur in distant organs. For women with this type of cancer, the test is now recommended to determine the best course of treatment following surgery and to spare them from unnecessary treatment.
"The racial disparities observed in this trial were not explained by differences in recurrence score or reported duration of antihormonal endocrine therapy," Dr. Albain said. "Nor were the differences explained by the type of chemotherapy (if used) or characteristics such as age, tumor size or grade. As such, our results suggest that biological differences may contribute to the significantly different outcomes of black women compared to others with breast cancer."
Dr. Albain continued: "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. 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."
TAILORx was sponsored by the National Cancer Institute, part of the National Institutes of Health, and designed and led by the ECOG-ACRIN Cancer Research Group. It also was supported by the Canadian Society Cancer Research Institute, Breast Cancer Research Foundation, Susan G. Komen for the Cure and the U.S. Postal Service Breast Cancer Research Stamp.
Limitations of the study include the retrospective nature of the analysis, lack of adequate power to address specific questions in the race/ethnicity subsets, and a reliance on self-reported adherence to hormone therapy.
The genomic test used in the trial was the Oncotype DX Breast Recurrence Score test from Genomic Health Inc., Redwood City, California.
Provided by ECOG-ACRIN Cancer Research Group
