Abstract P3-11-03: Treatment outcomes for early stage male breast cancer: a single centre retrospective case-control study
Authors: Kwong A , Visram H , Graham N , Balchin K , Petrcich W , Dent S 
Published: August 2014

Background: Male breast cancer (BC) is a rare disease with a reported incidence of 1%, and treatment strategies are therefore driven by studies conducted in the female BC population. There is also limited information with regards to treatment outcomes for men with early stage BC, particularly when compared with their female counterparts. The objective of this study is to compare the disease free survival (DFS) and overall survival (OS) of males with early stage BC compared to age and stage matched females in a single institution.

Methods: A retrospective matched case-control study was conducted to compare male and female pts treated for stage 0 to IIIB BC, at the Ottawa Hospital Cancer Centre, between 1981 and 2009. Matching of male and female pts was done based on age at diagnosis (+/− 2 years), year of diagnosis (+/− 1 year), and disease stage. Data regarding surgery, adjuvant radiation, chemotherapy, and endocrine therapy was collected. Overall survival and disease-free survival were calculated using Kaplan-Meir analysis.

Results: A total of 144 pts (72 female; 72 male) were eligible for this study; median age at diagnosis for both groups was 74 years (r: 30–85). Median follow-up was 54 months (r: 2–204) for males and 54 months (r: 4–241) for females. All 72 men underwent mastectomy compared to 38 females (53%). Forty-four (61%) females received adjuvant radiation therapy compared to 29 (40%) males. Twenty (28%) females received adjuvant chemotherapy, compared to 23 (31%) males. All female pts had estrogen receptor positive (ER+) disease, while 59 males (13 unknown) had ER+ disease. An equal number of males and females (79%) received endocrine treatment. The mean DFS for females was 127 months (25th percentile 33 months; median 104 months; 75th percentile 174 months), compared to 93 months (25th percentile 46 months; median 88 months; 75th percentile 112 months) for males (p = 0.62). Mean OS for females was 117 months (25th percentile 40 months; median 107 months; 75th percentile 136 months), and 124 months (25th percentile 48 months; median 90 months; 75th percentile 128 months) for males (p = 0.35). In multivariate analysis, the only parameter that affected both DFS and OS was stage at diagnosis (hazard ratio 0.42, 95% CI 0.18–1.00; hazard ratio 0.25, 96% CI 0.09–0.68).

Conclusions: This is one of the largest case-cohort studies to report on treatment outcomes of early stage male BC pts treated in a non-trial setting. Male pts received comparable systemic therapy (chemotherapy/endocrine) as their female counterparts and DFS and OS were similar. These results add to current evidence from population studies that male sex is not a poor prognostic factor for treatment outcomes in early stage BC. The development of a national male breast cancer registry would facilitate the evaluation of modern treatment strategies and patient outcomes in this population.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-11-03.