Abstract
BACKGROUND: Few studies in Hispanic women have examined the relation between adult body size and risk of premenopausal breast cancer defined by hormone receptor status. METHODS: The Breast Cancer Health Disparities Study pooled interview and anthropometric data from two large U.S. population-based case-control studies. We examined associations of overall and abdominal adiposity with risk of estrogen receptor- and progesterone receptor-positive (ER(+)PR(+)) and -negative (ER(-)PR(-)) breast cancer in Hispanic and non-Hispanic White (NHW) women, calculating ORs and 95% confidence intervals. RESULTS: Among Hispanics, risk of ER(+)PR(+) breast cancer was inversely associated with measures of overall adiposity, including young-adult and current body mass index (BMI). Risk was substantially reduced among those with high (above the median) young-adult BMI and current overweight or obesity. The findings for overall adiposity were similar for Hispanics and NHWs. In the subset of Hispanics with data on genetic ancestry, inverse associations of current BMI, and weight gain with ER(+)PR(+) breast cancer were limited to those with lower Indigenous American ancestry. For ER(-)PR(-) breast cancer, height was associated with increased risk, and young-adult BMI was associated with reduced risk. For all breast cancers combined, positive associations were seen for waist circumference, waist-to-hip ratio, and waist-to-height ratio in Hispanic women only. CONCLUSIONS: Our findings of body size associations with specific breast cancer subtypes among premenopausal Hispanic women were similar to those reported for NHW women. IMPACT: Adiposity throughout the premenopausal years has a major influence on breast cancer risk in Hispanic women.