Study shows gender differences in prognosis predictive utility of breast cancer recurrence score

The TAILORx study published last year offered good news for women with early-stage ER-positive breast cancer who scored at intermediate risk for recurrence according to a genetic assay test. The study indicated that chemotherapy after surgery provided little advantage in overall survival for these women, so they could forgo the treatment.

This conclusion may not directly apply to male patients with the same type of breast cancer. A new study by Vanderbilt-Ingram Cancer Center (VICC) researchers published in Clinical Cancer Research, a journal of the American Association for Cancer Research, indicates that a lower threshold is needed for male patients to predict mortality using the genetic assay, Oncotype DX^®, a commercial diagnostic test. The study's lead author is Fei Wang, MD, PhD, a visiting research fellow at Vanderbilt University, and its senior author is Xiao-Ou Shu, MD, PhD, MPH, Ingram Professor of Cancer Research and associate director for Global Health and co-leader of the Cancer Epidemiology Research Program at VICC.

"The recurrence score is associated with overall mortality in male breast cancer patients at a much lower threshold than that for female patients," the article stated. "Studies are needed to establish specific guidelines for recurrence scores for male breast cancer patients."

The researchers analyzed data of 848 male and 110,898 female breast cancer patients from the National Cancer Database, comparing overall mortality associated with recurrence scores. Breast cancer is rare in men, accounting for approximately 1% of all breast cancers.

"The observed differences in distribution as well as the prognosis predictive utility of recurrence score between men and women suggest that male breast cancer may have distinct biology and different prognostic factors compared to female patients," the authors wrote. "Studies have suggested that pathogenic mutations and epigenetic alterations involved in male breast carcinogenesis do not exactly overlap with those of women."