Agarwal A et. al.

Gender Disparity in Breast Cancer: A Veteran Population-Based Comparison.

Clin Breast Cancer 2021.
https://doi.org/10.1016/j.clbc.2021.01.013.

Breast cancer is the most common cancer in women; however, it is quite rare in men. One in eight women in the United States will develop breast cancer, but only 1 in 1,000 men will experience breast cancer in a lifetime. The age of onset is later in men with the typical age of diagnosis of male breast cancer (MBC) being between the seventh and eighth decade of life. Survival for men with breast cancer is generally worse than that of women. Extensive research on female breast cancer (FBC) has led to improved overall survival and reduced rate of mortality. It is unclear why improvements in mortality rate for MBC have not been made. This disparity is currently attributed to lack of ability to detect breast cancer in males at an early stage and lack of individualized treatment options to improve outcomes.

Aggarwal et al looked at patients diagnosed with breast cancer between 1998 and 2016 at 152 Veteran Medical Centers. The primary goal of this study was to compare breast cancer patient demographics, breast cancer characteristics and outcomes for male and female veterans. They identified 1,528 MBC patients and 7,336 FBC patients. The average age of diagnosis of breast cancer was higher in the MBC versus FBC patients. More MBC patients presented with higher disease stage (stage 3 and 4) than FBC patients. More MBC had hormone positive breast cancer and received hormone therapy when compared to FBC. Less MBC than FBC received chemotherapy and radiation independently. Strikingly, 42% of MBC while 20% of FBC died during this study. Male patients had a higher death rate of 1.285 compared to females after controlling for age, race, stage, and grade as driving factors for this difference.

Much of our treatment of MBC is based on our knowledge and research regarding FBC. However, there is a difference in mortality and outcomes as shown by the work of Aggarwal et al. There is speculation as to why there is such a disparity in outcomes between MBC and FBC. Some propose it is due to later presentation and higher stage at time of diagnosis of MBC. Others believe there is variation in tumor biology with MBC. In addition, this study by Aggarwal et al highlights veteran exposure to hazardous materials during their military deployments as an additional factor that could lead to worse prognosis. While MBC is less common, outcomes are much worse and additional research is needed to better understand this disparity.