Assessment of Prognostic and Therapeutic Factors in Male Breast Cancer: An Observational Study of a Southwest Spanish Single Center

Background: Male breast cancer (MBC) accounts for less than ۱% of breastcancer, requiring extrapolation of results from studies in women. The aim of thestudy is to evaluate prognostic and therapeutic factors with special focus inendocrine treatment (ET) on the disease outcome.Methods: Observational, retrospective, single-center study of ۵۳ MBC treatedbetween January ۱۹۹۷ and December ۲۰۱۸ participated in the study. Among theparticipants, ۴۸ patients had a performance status (PS) ۰-۱ (۹۱%), ۴۸ werehormone-receptor-positive (۹۱%) and ۴ were human epidermal growth factor ۲receptor (HER۲) positive (۸%). A total of ۴۵ patients (۸۵%) were treated with ET,with ۳۶ patients (۶۸%) receiving treatment in an adjuvant setting. The associationanalysis was performed using Chi-square test and survival was estimated usingKaplan-Meier with SPSS v۲۵.Results: The cohort had a median age of ۶۸ years old (range: ۴۰-۸۸). We foundthat ۸۴% had a non-metastatic breast cancer. A breast cancer gene (BRCA)analysis was carried out in ۴۳% of the patients, showing BRCA۲ mutated in ۲۶.۱%of those analyzed, without obtaining a benefit in overall survival (P=۰.۶۹۸). Theanalysis showed higher ۵-year overall survival (OS) for PS ۰ (P=۰.۰۱۰), absenceof vascular invasion (P=۰.۰۳۳), Ki۶۷ ≤۱۴% (P=۰.۰۴۱) and absence of metastasis atdiagnosis (p<۰.۰۰۰۱). Patients receiving adjuvant ET above ۵ years had a longermedian OS (۸۹ vs ۶۹.۶ months, P=۰.۰۲۴), disease-free survival (DFS), and distantrelapse (۸۴ vs ۴۸ months; P=۰.۰۰۵, and P=۰.۰۰۲, respectively).Conclusions: Several prognostic factors for male breast cancer have beendescribed. Noteworthy, patients receiving adjuvant ET above ۵ years had a higherOS and DFS. BRCA did not show prognostic value in OS in this cohort. Furtherstudies with larger sample size are necessary.

Keywords:

Breast cancer , BRCA , endocrine therapy , men , prognosis