Body size and breast cancer risk in black women and white women - The Carolina Breast Cancer Study

The relation between body size and breast cancer risk was investigated in a population-based, case-control study of Black women (350 cases, 353 contro ls) and White women (523 cases, 471 controls) from North Carolina, aged 20- 74 years in 1993-1996. Logistic regression analyses compared tertiles of ea ch body size variable, adjusting for age and breast cancer risk factors (re sults shown for highest relative to lowest tertile). Among premenopausal wo men, body mass index (kg/m(2)) was inversely associated with breast cancer (odds ratio (OR) = 0.46, 95% confidence interval (CI): 0.26, 0.80) for Whit es but not for Blacks. There was essentially no association among postmenop ausal women. Higher waist/hip ratio, adjusted for body mass index, increase d risk for all women. Odds ratios for Black and While premenopausal women w ere 2.50 (95% CI: 1.10, 5.67) and 2.44 (95% CI: 1.17, 5.09), respectively; odds ratios for Black and White postmenopausal women were 1.62 (95% CI: 0.7 0, 3.79) and 1.64 (95% CI: 0.88, 3.07), respectively. Findings for body mas s index differed among Black women when stratified by age (<50 years) (OR = 0.50, 95% CI: 0.25, 1.07) instead of menopausal status. Thus, the associat ions of breast cancer with body mass index and waist/hip ratio among Black women are similar to those documented for Whites, despite different body si ze profiles on ave rage.