Demographics and survival outcomes of stage IV male breast cancer: A retrospective analysis of SEER database.

Abstract

11142 Background: Male Breast Cancer (MBC) is a rare malignancy accounting for <1% of all breast cancer cases in the United States. It is often lately diagnosed due to lack of awareness leading to substantial morbidity and mortality. Previous studies revealed higher risk of death among males compared to females across all stages, but little known about the impact of Hormone Receptor (HR) and Human Epidermal growth factor Receptor 2(HER 2) statuses on prognosis and survival among MBC patients. So, we aim to study the survival outcomes of stage IV MBC patients using SEER (Surveillance, Epidemiology, and End Results) data. Methods: A retrospective analysis was conducted using a SEER database and identified stage IV MBC cases (Any T, Any N, M1) diagnosed between 2010-2015. The selection of these years is based on the reporting of HER2 status on SEER database starting from 2010 and to ensure a current period and a minimum of 5 years of follow-up. Patient demographics, tumor HR/HER 2 status and survival data were extracted and analyzed. Subgroup analyses were performed to show the correlation between HR/HER 2 status and survival. Results: The study included 144 patients. 59.7%(86/144) were above 60 years of age. Majority were Caucasians up to 68.1%(98/144) followed by African Americans 18.7% (27/144), Hispanics 6.9%(10/144) and Asians/Pacific Islanders 6.2%(9/144). Among the subtypes, the most common was HR+/HER2- consisting of 69.4%(100/144) followed by HR+/HER2+ 19.4%(28/144), HR-/HER2- 9.7%(14/144), HR-/HER2+ 1.4%(2/144). The median overall survival varied among different subtypes of breast cancer and was noted to be 31.5 months, 25 months, 4.5 months and 10 months among HR+/HER2-, HR+/HER2+, HR-/HER2- and HR-/HER2+ respectively (Table). In the comparison between HR+/HER2+ and HR-/HER2-, the risk of death differed significantly, as indicated by a hazard ratio of 0.26 (95% CI 0.12-0.56, p = 0.001), highlighting a poor survival of HR-/HER2-. Conclusions: This retrospective analysis provides valuable insights into the demographics and survival outcomes of stage IV MBC patients. Triple negative (HR-/HER2-) subtype continues to have poor outcomes in males as well, emphasizing the need to explore novel treatment strategies to improve outcomes for this unique patient population. Although, treatment regimens for MBC are extrapolated from women, the disparity in survival across all subtypes requires the need to get more men on breast cancer clinical trials when feasible. [Table: see text]