Rising Incidence of Colorectal Cancer in Young Adults Corresponds With Increasing Surgical Resections in Obese Patients.

OBJECTIVES: Strong evidence links obesity to esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), and pancreatic cancer (PC). However, national-level studies testing the link between obesity and recent temporal trends in the incidence of these cancers are lacking. METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER) to identify the incidence of EC, GC, CRC, and PC. Cancer surgeries stratified by obesity (body mass index ≥30 kg/m) were obtained from the National Inpatient Sample (NIS). We quantified trends in cancer incidence and resections in 2002-2013, across age groups, using the average annual percent change (AAPC). RESULTS: The incidence of CRC and GC increased in the 20-49 year age group (AAPC +1.5% and +0.7%, respectively, P < 0.001) and across all ages for PC. Conversely, the incidence of CRC and GC decreased in patients 50 years or older and all adults for EC. According to the NIS, the number of patients with obesity undergoing CRC resections increased in all ages (highest AAPC was +15.3% in the 18-49 year age group with rectal cancer, P = 0.047). This trend was opposite to a general decrease in nonobese patients undergoing CRC resections. Furthermore, EC, GC, and PC resections only increased in adults 50 years or older with obesity. DISCUSSION: Despite a temporal rise in young-onset CRC, GC, and PC, we only identify a corresponding increase in young adults with obesity undergoing CRC resections. These data support a hypothesis that the early onset of obesity may be shifting the risk of CRC to a younger age.