Survival in male breast cancer over the past 3 decades

Abstract

Background: Breast cancer mortality in women has declined statistically significantly over the past several years. In men, it is unclear whether survival has changed over time. We evaluated changes in breast cancer-specific survival (BCSS) and overall survival (OS) in male breast cancer over the past 3 decades.

Methods: We evaluated men diagnosed with breast cancer between 1988 and 2017, reported in the Surveillance, Epidemiology, and End Results registry. Patients were categorized into 3 groups by year of diagnosis: 1988-1997, 1998-2007, and 2008-2017. BCSS and OS were estimated by Kaplan-Meier, and differences between groups were compared by log-rank test. Multivariable Cox regression evaluated the independent association of year of diagnosis with BCSS and OS. All tests were 2-sided.

Results: We included 8481 men. Overall, BCSS at 5 years was 83.69%, 83.78%, and 84.41% in groups 1988-1997, 1998-2007, and 2008-2017, respectively (P = .86). There was no statistically significant difference in BCSS between the 3 groups within each stage of disease. Among all patients, OS at 5 years was 64.61%, 67.31%, and 69.05% in groups 1988-1997, 1998-2007, and 2008-2017, respectively (P = .01). In adjusted Cox models, each additional year of diagnosis had no statistically significant association with BCSS (hazard ratio = 1.00, 95% confidence interval = 0.99 to 1.01, P = .75), but there was statistically significant improvement in OS (hazard ratio = 0.99, 95% CI = 0.98 to 0.99, P = .009).

Conclusions: Over the past 3 decades, there has been no statistically significant improvement in BCSS in male breast cancer. Changes in OS over time are consistent with increasing life expectancy. Efforts to improve BCSS in male breast cancer are warranted.