Diet and cancer of endocrine target organs.

The role of diet in the etiology of cancer of the breast and endometrium is considered. Geographic variation in rates, effects of migration, consequences of exogenous hormone use, and other epidemiologic factors are reviewed. Cancer of the endometrium is related to diet probably through simple caloric excess. The excess is reflected in obesity and the consequent overproduction of estrone, a natural but carcinogenic human estrogen. Diet may also influence breast cancer risk somewhat through the same mechanism. But this mechanism probably would not explain a large proportion of the disease. It is possible that, in addition, some specific dietary factor, for example, saturated fat, is causally related to breast cancer. Such a relationship would probably be mediated through an endocrine mechanism.