72P - Male breast cancer receptor sub-types: Demographics, tumor characteristics and short term survival outcomes

Abstract

Introduction: Male breast cancer constitutes less than 1% of all breast cancers in the United States. The characteristics and outcomes for different receptor sub-types of male breast cancer is not well known. Methods: We obtained case data from National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program for all male breast cancers diagnosed since 2010. Patients were excluded if their receptor subtype was unknown. 922 male breast cancer patients met inclusion criteria. Of these, 757(82%) were hormone receptor positive and Her2 receptor negative (HR + /HER2-), 135(15%) were hormone receptor and Her2 receptor positive(HR + /HER2+), 19(2%) were triple negative (HR-/HER2-), 11(1%) were hormone receptor negative and Her2 positive (HR-/Her2+) breast cancers. Results: Triple negative breast cancers were diagnosed at a significantly younger age compared to hormone receptor positive breast cancers. There were no significant differences in the racial composition and histology of different subtypes of male breast cancers. The overall stage and nodal status was barely insignificant (p = 0.052 and p = 0.051 respectively) between the different subtypes. However, there were significant differences between the groups in terms of the histologic grade, tumor stage and metastasis status at diagnosis. There was significant difference in survival on Kaplan Meier plots between the different receptor subtypes of male breast cancer. The one year survival for different receptor subtypes is presented in table 1. Conclusions: Significant differences were noted in tumor characteristics between different subtypes of male breast cancers. Also, triple negative breast cancers were more likely to be diagnosed at a younger age and carried the worst one year survival. Further research is needed in this area to better characterize the role of receptor subtypes in tumor pathology and outcome in male breast cancer patients.Tabled 1One year survival ratesAll male breast cancersHR + /HER2-HR-/HER2-HR-/HER2 +HR + /HER2 +One year overall survival95.0%96.7%67.9%90.0%89.9%One year cause specific survival96.6%98.2%67.9%90.0%92.2% Open table in a new tab Disclosure: All authors have declared no conflicts of interest.