Abstract 869: Body mass index, weight gain, and physical activity during adulthood in relation to colorectal cancer risk

Abstract

Abstract Background: The impact of obesity/overweight, weight gain, and physical activity during adulthood on colorectal cancer (CRC) risk is not clear. To examine the associations between body mass index (BMI), weight gain, and physical activity during adulthood and CRC risk, we conducted a case-control study of incident CRC. Methods: Incident CRC case subjects were recruited from the University of Texas MD Anderson Cancer Center in Houston, Texas; healthy control subjects without a history of cancer, except non-melanoma skin cancer, were identified and recruited using random digit dialing. Epidemiologic data were collected by in-person interview. Unconditional logistic regression and regression spline were performed to obtain odds ratios (ORs). All statistical tests were two-sided. Results: A total of 524 non-Hispanic white case subjects and 1,053 healthy control subjects who were 40 years or older were included. In multivariate analysis, obesity (BMI ≥ 30) and overweight (BMI between 25 and 30) at age 20 years were significantly associated with a 2.4-fold (OR = 2.39, 95% confidence interval [CI] = 1.38 - 4.13, P = .002) and 1.6-fold (OR = 1.60, 95% CI = 1.19 - 2.14, P = .002) increased risk of CRC, respectively. Similarly, obesity and overweight at age 40 years were each significantly associated with a 2.1-fold (OR = 2.11, 95% CI = 1.49 - 2.99, P < .0001) and 1.7-fold (OR = 1.74, 95% CI = 1.32 - 2.30, P < .0001) increased risk of CRC. In addition, moderate and massive weight gain from age 20 to 40 years were associated with increased CRC risks, although this increase did not reach statistical significance. Moderate physical activity was significantly associated with a reduced risk of CRC (OR = 0.60, 95% CI = 0.44 - 0.81, P = .001). Conclusions: Obesity/overweight and physical activity during adulthood may influence susceptibility to CRC; also, our data suggest that weight gain during childhood and adolescence may play a more important role than weight gain during adulthood in CRC development. Citation Format: Huakang Tu, Xia Pu, Carrie Daniel-MacDougall, Stephanie C. Melkonian, Yuanqing Ye, Gottumukkala S. Raju, Scott Kopetz, Xifeng Wu. Body mass index, weight gain, and physical activity during adulthood in relation to colorectal cancer risk. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 869. doi:10.1158/1538-7445.AM2015-869