Abstract P4-17-07: Demographics and survival in male breast cancer: An updated analysis of SEER database

Abstract

Abstract Background: Male breast cancer is rare accounting for less than 0.5% of all cancer diagnoses in men. Previous epidemiological studies reported conflicting results regarding the prognosis of male breast cancer in comparison to female breast cancer. As treatment for breast cancer has improved significantly, we conducted this study to evaluate male breast cancer characteristics and mortality. Methods: All patients diagnosed with breast cancer between 2010 and 2015 from the population-based cancer registries of the Surveillance Epidemiology and End Results program (SEER) were analyzed. Descriptive statistics, Kaplan-Meier analysis and COX regression model were used to examine the data. Results: A total of 380,116 cases of breast cancer were found including 2,978 cases of male breast cancer. The age-adjusted incidence rate for male breast cancer during the study period was 1.2 per 100,000 individuals per year which is slightly higher than the rate during the 10 years period preceding our study date (1.1 per 100,000 per year). Out of all male breast cancer patients, 80.7% of them were white, 14.6% black and 4.7% from other races. The median age of diagnosis was 68. 34% of male breast cancer patients were diagnosed with stage I, 41.6% with stage II, 16.2% with stage III and 8.2% with stage IV. 97% of male breast cancer cases were ER/PR positive and 11.9% were HER2 positive. 5-year survival rate for male breast cancer patients was 90% for stage I, 86% for stage II, 78% for stage III and 28% for stage IV. Cox proportional-hazards model revealed a slight increase in mortality associated with male breast cancer in comparison to female breast cancer (adjusted hazard ratio, 1.15; 95% confidence interval, 1.06 to 1.24; P<0.01). Conclusions: Male breast cancer represents less than 1% of breast cancer cases. Its age-adjusted incidence rate has slightly increased. It is mostly diagnosed as early stage with positive hormone receptors status. After controlling for other risk factors, male breast cancer patients have a worse survival outcome than female patients. Citation Format: John Khoury, Nwabundo Anusim, David Macari, Ishmael Jaiyesimi. Demographics and survival in male breast cancer: An updated analysis of SEER database [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-17-07.