BODY-SIZE AND BREAST-CANCER RISK AMONG WOMEN UNDER AGE 45 YEARS

In a multicenter population-based case-control study that included 1,5 88 cases and 1,394 controls less than age 45 years, the authors examin ed the relation of adult body size and breast cancer risk among young women. Breast cancer patients and healthy controls were identified in Atlanta, Georgia; Seattle/Puget Sound, Washington; and central New Jer sey. Cases were newly diagnosed with in situ or invasive breast cancer during the period of May 1, 1990, through December 31, 1992. Anthropo metric variables thought to reflect early environmental factors (e.g., height, sitting height, frame size), obesity, and body fat distributi on were measured directly. Height, but not sitting height or frame siz e, was a breast cancer risk factor. Risk of the disease was increased 46 percent among women in the fourth quartile of height (>167 cm) comp ared with women in the first quartile (<159 cm). Body weight, but not body fat distribution, was related to breast cancer risk. Risk of the disease was 35 percent lower among women in the highest quartile of Qu etelet index (>28.8 kg/m(2)) compared with women in the lowest quartil e (<22.0 kg/m(2)). Risk of the disease was increased about 2.1-fold (9 5 percent confidence interval 1.2-3.8) among women who were thin and t all compared with women who were heavy and short. Thus, breast cancer risk was increased substantially among younger women with a linear bod y type.