A Prognostic Analysis of Male Breast Cancer (MBC) Compared with Post-Menopausal Female Breast Cancer (FBC)

Background Male breast cancer (MBC) is known to be rare compared with female breast cancer (FBC) and to account for only 1% of all breast cancers. To date, male patients diagnosed with breast cancer are normally treated based on the guidelines for FBC. Specifically, studies have found that diagnosing and treating MBC patients under the guidelines for the treatment of post-menopausal FBC are more favorable than are those of pre/peri-menopausal FBC from a physiological perspective because MBC and post-menopausal FBC patients show high estrogen receptor (ER) expression in the tumor and low estrogen expression in the body. In this medical study, we aimed to examine whether MBC actually has the same prognosis as post-menopausal FBC. Method We identified MBC patients who were diagnosed as operable and who completed clinical treatment and we used follow-up data that were collected from January 2001 to January 2011. Each MBC patient was paired with four FBC patients who were diagnosed within the same period (two were pre/peri-menopausal, and two were post-menopausal). We compared disease-free survival (DFS) and overall survival (OS) among three groups, i.e., pre/peri-menopausal FBC (group A), post-menopausal FBC (group B) and MBC (group M), using the Kaplan-Meier method and a Cox proportional hazards regression model. We also evaluated the clinical characteristics of breast cancer patients using t-tests and chi-square tests. We used ten consecutive years of data that were collected at Zhejiang Provincial Cancer Hospital. Results We identified 91 MBC cases for group M, 182 FBC cases for group A and 182 FBC cases for group B. The median follow-up period was 112 months. MBC cases were much more frequently ER positive than those of group A and group B (p