Epidemiology of human breast cancer

Abstract

The descriptive and analytic epidemiology of breast cancer is reviewed. A strong new indicator, age at first birth, has emerged. Lactation is not protective against breast cancer, but multiparity is associated with low breast cancer risk in a noncausal way. The major causal hypotheses are discussed. The first, genetic, is based on the familial aggregation of breast cancer, but there is no recognizable pattern of inheritance. The viral hypothesis remains unevaluated. The endocrine hypotheses, relating to progesterone, prolactin, androgens, and estrogens, are reviewed in detail. (33 references.)