Second cancers in patients with male breast cancer: a literature review

Purpose  The risk of second malignancies among female breast cancer patients has been studied for decades. In contrast, very little is known about second primary tumors in men. Risk factors for breast cancer in men, including genetic, hormonal and environmental factors, provide parallels to the etiology of breast cancer in women. This review considers the literature related to the risk of developing a second cancer in patients with male breast cancer. Materials and methods  A systematic review of the literature between 1966 and 2007 was conducted and acceptable articles used for analysis. All retrieved articles were screened to identify any papers that had been missed. Studies were included if they discussed the risk of subsequent malignancy in patients with male breast cancer. Results  Patients with history of male breast cancer have an increased risk of a second ipsilateral, or contralateral breast cancer (standardized incidence ratio 30–110). The risk of subsequent contralateral breast cancer was highest in men under 50 years of age at the time of the diagnosis of the initial cancer. The data on non-breast second primary cancers is diverse. One study has suggested an increased incidence of cancers of the small intestine, prostate, rectum and pancreas, and of non-melanoma skin cancer and myeloid leukaemia. Other investigators did not find an increase in the overall risk of subsequent cancer development in men diagnosed initially with primary breast cancer. Although sarcoma, lung and esophageal cancers are well recognized complications of radiation therapy for female breast cancer, there is no evidence for the association of these cancers following radiation therapy in male breast cancer. Conclusions  Although the incidence of second primary cancer in patients with primary male breast cancer requires further study, male breast cancer survivors should probably undergo periodic screening for the early detection of second breast cancers and other adverse health effects.