Familial bilateral breast cancer.

The occurrence of bilateral breast cancers in three members of one family is reported. In two members, evidence of a distinct primary lesion in each breast was verified. The occurrence of unilateral breast cancer and other cancers in other members of the family was surveyed. Recommendations for early detection and surveillance in familial breast cancer at the present time should be aggressive and close follow-up of the affected members. Absence of reliable markers preclude effective surveillance for early detection or susceptibility.