[Familiality of breast cancer and hereditary factors].

Recent results in family studies of breast cancer were overviewed. Site specific familial aggregation of the disease, with no significant increase of other cancers, by itself suggests a specified etiological role of the familial predisposition. Probably it must be interpreted by a synergism of some genetic and environmental factors. Among the cases in Cancer Institute Hospital, familially predisposed patients showed a significant differences in younger age at menarche and taller stature compared with the other patients. It has been frequently observed that a risk for the disease in the relatives of a patient is higher in pre-than in postmenopausal onset. It appears, however, that the age specific incidence rate among those women with a positive family history is consistently higher than that of the general population in any age classes except the premenopausal period. Findings obtained by recent endoclinological studies point out the concept that a possible genetic abnormality associated with the breast cancer disposition should be pertaining to the metabolism of ovarian hormone.