Nutrition and age at first birth in breast-cancer risk.
Urban/rural breast-cancer incidence ratios in the state of Iowa for 1950 and 1969-71 were contrasted with corresponding urban and rural distributions of age-at-first-birth and population nutrition, variable measured approximately 15 years before each morbidity survey and putatively related to breast-cancer incidence. Over the study interval, the decline in the urban/rural breast-cancer incidence ratio correlated better with changing nutritional patterns than with changing age-at-first-birth.
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D007484:Iowa; D008423:Maternal Age; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena; D011247:Pregnancy; D012306:Risk; D012424:Rural Population; D014505:Urban Population