[The breast cancer-prone family: clinical study of familial breast cancer].

Familial breast cancer are clinically characterized by early age of onset, the increased frequency of multiple primary malignant neoplasms including bilateral breast cancer and non-left-side dominance with regard to the site of onset. The genetic consideration of the pedigrees suggests that familial clustering of breast cancer is related to the autosomal dominance of susceptibility, polygenes and incomplete penetrance. The additive effects obtained by combining the genetic with the environmental factors are recognized in familial breast cancer. Clinical surveys and follow-ups of breast-cancer-prone families are required to facilitate the early detection and treatment.