Treatment Patterns and Prognostic Factors in Stage I-III Male Breast Cancer: Multicentric Study of Turkish Socİety for Radİatİon Oncology Breast Cancer Study Group (Trod 06-013)

Abstract

Abstract Aim Clinicopathologic,demographic characteristics, and treatment patterns of patients diagnosed with male breast cancer (MBC) and treated with adjuvant radiotherapy (RT) in the last 20 years were retrospectively analyzed. Material and Method: Between January 2000 and January 2021, 207 patients diagnosed with MBC, all of whom underwent RT, were recruited from 25 centers.Kaplan-Meier method was used to determine the rates of overall survival (OS),progression-free survival (PFS),and loco-regional recurrence-free survival(LRRFS).Multivariate Cox regression analysis was used to determine the relationship between histopathologic data and survival and prognostic factors. Results Estrogen receptor (ER) was positive in 93% and progesterone receptor (PR) in 83.4% patients.Human epidermal growth factor 2 (HER2) was negative in 75.4%.In multivariate analysis; > 5 cm tumor, > 50 years of age, pathological lymph node stage(pN) as pN2 or pN3, pathological tumor stage (pT) as pT3 or pT4, TNM stage III, nipple invasion, skin invasion, and ER negativity was related with shortened OS.These prognostic factors for PFS and LRRFS were similar except ER status.There was no difference in survival rates between pN0 and pN1 groups nor pT1 and pT2 groups.OS and LRRFS were longer in patients treated with endocrine therapy (ET). However,there was no difference between the tamoxifen (TMX) group and the aromatase inhibitor (AI) + luteinizing hormone-releasing hormone agonist (LHRH-a) group (p > 0.05). Conclusion The most important poor prognostic factors in MBC were tumor size exceeding 5 cm,pN2 and above, and age > 50 years at first diagnosis.We also found that adjuvant ET was beneficial for survival,but there was no difference between the AI and TMX groups.