Abstract
Research strongly suggests that lower overall adiposity and higher central adiposity are independent risk factors for premenopausal breast cancer in the general population. We aimed to test the possibility that these factors may contribute to familial risk of premenopausal breast cancer. A convenience sample of healthy women, ages 25–49, was recruited to yield three study groups: (1) Women with first‐degree family histories of premenopausal breast cancer, operationally defined as being diagnosed prior to age 50 (Group FH < 50, n = 39); (2) Women with first‐degree family histories of postmenopausal breast cancer, operationally defined as being diagnosed at age 50 or after (Group FH ≥ 50, n = 33); and (3) Women without a history of breast cancer in first‐degree relatives (Group FH−, n = 132). Multinomial logistic regression analyses, including possible confounders, waist circumference, and BMI, revealed a lower BMI among FH < 50 compared to either FH− (OR = 0.72; 95% CI = 0.59–0.87), or FH ≥ 50 women (OR = 0.75; 95% CI = 0.60–0.95), and higher waist circumferences in FH < 50 compared to either FH− (OR = 1.15; 95% CI = 1.06–1.25), or FH ≥ 50 women (OR = 1.16; 95% CI = 1.05–1.28). No group differences were seen for waist skinfold measures. These results support the possibility that differences in patterns of adiposity may contribute to familial risk of premenopausal breast cancer, and suggest the importance of conducting large scale, population‐based studies of the link between body size characteristics and familial breast cancer risk. Am. J. Hum. Biol., 2008. © 2007 Wiley‐Liss, Inc.