Risk of breast, endometrial, colorectal, and renal cancers in postmenopausal women in association with a body shape index and other anthropometric measures.

Abstract

A body shape index (ABSI) has been proposed as a possible improvement over waist circumference (WC) as a marker of abdominal adiposity because it removes the correlation of WC with body mass index (BMI) and with height. We assessed the association of ABSI with four obesity-related cancers compared to that of other anthropometric measures of adiposity. We used data from the Women's Health Initiative, a large cohort of postmenopausal women, recruited between 1993 and 1998 and followed until September 2013, to assess the associations of ABSI and other anthropometric measures with risk of cancers of the breast, endometrium, colorectum, and kidney. The four comparison anthropometric measures were BMI, WC, waist circumference-to-height ratio (WHtR), and waist-hip ratio (WHR). Over a median of 12.7years of follow-up, among 143,901 women, we identified 7,039 invasive breast cancers, 1,157 endometrial cancers, 1,908 colorectal cancers, and 376 kidney cancers. We used Cox proportional hazards models to estimate the association of quintiles of the five measures with risk of the four cancers. Unlike the other anthropometric indices, ABSI was not associated with increased risk of breast or endometrial cancer. BMI and WC were comparable as predictors of breast and endometrial cancer, and these associations were unchanged after mutual adjustment. For colorectal and kidney cancers, ABSI was a significant predictor comparable to BMI; however, WC showed the strongest association with colorectal cancer, and WC, WHtR, and WHR all showed stronger associations with kidney cancer. In contrast to other anthropometric measures, ABSI showed no association with risk of breast or endometrial cancer and was more weakly associated with risk of colorectal and kidney cancers compared to more established measures of central adiposity.