Familial breast cancer: report of a family pedigree.

Following a report of several relatives suffering from breast cancer, the occurrence of neoplasms in 3 generations of a large family was carefully checked. Members of one out of 8 branches were found to have a high incidence of breast cancer with 6 women affected, 4 of them under the age of 40. As well as early onset, these women presented other features typical of "breast cancer families": bilateral breast cancer, other second primary tumours, ovarian cancer in the daughter of one affected patient, and benign breast disease in the sister of another.