PURPOSE: We investigated the relationship between BRCA mutations and the 
distribution of familial cancers other than breast or ovary in high-risk breast 
cancer patients.
METHODS: PATIENTS WITH BREAST CANCER WHO HAD AT LEAST ONE OF THE FOLLOWING RISK 
FACTORS WERE ENROLLED: reported family history of breast or ovarian cancer; 40 
years of age or younger age at diagnosis; bilateral breast cancer; or male 
gender. Genetic testing for BRCA mutation and questionnaires about personal and 
family histories of malignancies were performed.
RESULTS: Among the 238 eligible patients, 49 (20.6%) patients had BRCA1/2 
mutations, which were more frequent in patients with multiple risk factors 
(p<0.0001). There were 271 members of 156 (65.5%) families who had histories of 
other primary cancer. The distribution of the families was 119 (63.0%) and 37 
(75.5%) in the BRCA-negative and positive group, respectively (p=0.0996). 
Multiple familial cancers occurred in 70 families, which were significantly more 
frequent in BRCA-positive families (p=0.0034). By ordinal logistic regression, 
the occurrence of multiple familial cancers was associated with BRCA mutations 
(p=0.0045), not with other risk factors. The most common site of disease was the 
stomach, which is the most common in nationwide. And the proportional incidence 
of pancreatic cancer (6.8%) was significantly higher than that of nationwide 
cancer statistics (2.4%, p=0.0137).
CONCLUSION: BRCA mutations in high-risk breast cancer patients were associated 
with multiple risk factors and multiple family members with other primary 
cancers. Genetic counseling based on accurate information should be provided to 
families with BRCA mutation carriers.