BRCA2 gene mutations in Slovenian male breast cancer patients.

Male breast cancer (MBC) is a rare disease, comprising less than 1% of breast cancer patients in Slovenia. Some inherited cases are due to the mutations of BRCA1 or BRCA2 genes. There is no information available about the frequency of BRCA gene mutations in Slovenian MBC population. The purpose of this study was to characterize BRCA germline mutations in Slovenian MBC patients. Forty-one patients who were diagnosed with breast cancer at the Institute of Oncology Ljubljana between 1970 and 2006 were proposed to take part in this study. Of them, 27 agreed to follow a genetic counseling session and 25 patients agreed to provide a blood sample for genetic testing. The BRCA1 and BRCA2 genes from the MBC patients were screened for four highly recurrent mutations in the Slovenian population. When an additional breast cancer case or an ovarian cancer was present in the family, a more extended analysis was performed. No BRCA1 mutations were found. A BRCA2 gene mutation was identified in four MBC patients. Three of them carried the Slovenian founder mutation IVS16-2A>G. All four mutations were confined to the patients with a family history of breast cancer. Among the MBC patients with a family history of breast cancer in the first- or second-degree relatives, the frequency of BRCA2 gene mutation was 50%. The median age of the patients with a BRCA2 gene mutation was 60 years, not significantly different from those without a mutation. The BRCA2 mutations were diagnosed in 16% of our MBC patients.