Obesity and Gastrointestinal Cancer: A Life Course Perspective

Abstract

Gastrointestinal (GI) cancers account for about 27% of new cancer cases and 37% of cancer deaths globally, 1 with colorectal cancer (CRC) as the most common type in the United States. 2 Obesity (defined as body mass index [BMI] Ն30, where BMI is calculated as weight in kilograms divided by height in meters squared) has tripled in prevalence in the past several decades and is an established risk factor for multiple GI cancers, including esophageal adenocarcinoma, gastric cardia, liver, gallbladder, pancreatic, and colorectal cancer. 3 However, most epidemiologic studies examined BMI at one time point, missing the opportunity to delineate the contribution of adiposity throughout the life course. In this issue, Loomans-Kropp et al 4 explored the associations between BMI at early adulthood (aged 20 years), middle adulthood (aged 50 years), and later adulthood (aged Ն55 years), as well as BMI changes (from early or middle adulthood to later adulthood) with risk of CRC and non-CRC GI cancers (including esophageal, gastric, liver, and pancreatic cancer), using data from 135 161 participants aged 55 to 74 years at enrollment from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (1993-2014). In the baseline questionnaire, participants self-reported weight and height at 20 years of age, 50 years of age, and current weight and height. During up to 21 years of follow-up, 2803 incident CRC cases and 2285 non-CRC GI cancer cases occurred. Overall,