Similarities and differences in the characteristics and primary treatment of breast cancer in men and women – a population based study (Sweden)

Abstract

Purpose. Male breast cancer (MBC) is an uncommon disease. In the absence of randomized studies, current guidelines are mainly based on data on the management of female breast cancer (FBC). In light of concerns regarding the quality and extent of management in men, the aim of the present study was to investigate whether there are differences in tumor characteristics, treatment and outcome in male compared with FBC patients. Methods. Cohorts of male and female breast cancer were retrospectively analyzed. All male patients diagnosed with invasive breast cancer between 1993 and 2007 were identified from the Regional Breast Cancer Register of the Uppsala-Örebro Region in Sweden. To increase the power of the study and obtain comparable cohorts we sampled four FBC patients (n = 396) for each MBC patient (n = 99) with similar age at diagnosis and time of diagnosis. Results. No differences were seen in stage at diagnosis between MBC and FBC. Men underwent mastectomy more often than women (92% vs. 44%, p < 0.001). Radiotherapy was delivered less often to MBC than FBC (44% vs. 56%, p = 0.034), but radiotherapy given after mastectomy (44% vs. 39%, p = 0.47) did not differ between the groups. No differences were found regarding adjuvant chemotherapy (16% vs. 21%; p = 0.31) or adjuvant endocrine therapy (59% vs. 52%, p = 0.24). Both overall survival (41% vs. 55%, p = 0.001) and relative survival (74% vs. 88%, p = 0.015) were inferior in MBC compared to FBC. Conclusion. Concerns regarding less extensive treatment in MBC patients were not supported by this study. Although no differences in the stage of the disease or treatment intensity could be demonstrated, outcome was inferior in the male group.

Acknowledgements

We are grateful to the Regional Research Foundation in Uppsala-Örebro, the Lion's Cancer Foundation, University Hospital, Uppsala and Västmanlands Research Foundation for financial support. We also would like to acknowledge Professor Carl Blomqvist for skillful advice and Associate Professor Henry Letocha for skillful advice and language support.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.