[A case of familial breast cancer]

The occurrence of breast cancer in 5 members of a family is reported. No specificity of the location, staging or histological typing of the lesions was observed in these cancers. But the characteristics of "hereditary breast cancer", early onset and the occurrence of metachronous double cancers, were observed. As for heredity, it is suspected to be autosomal dominant trait; on the other hand it is more appropriate to assume a poly genic pattern. Recognizing the importance of familial cancer occurrence, it may be possible to detect early cancerous lesions in family members.