1130 Bariatric Surgery Is Associated With a Recent Temporal Increase in Colorectal Cancer Resections, Most Pronounced in Adults <50 Years of Age: A 2006-2013 National Analysis

Abstract

INTRODUCTION: The incidence rates of early-age onset colorectal cancer (CRC) are rapidly rising in the United States. In parallel, evolving evidence suggests an unexpected increase in long-term risk of CRC after bariatric surgery (BRS). BRS utilization expanded in the past three decades, however limited knowledge exists regarding the impact of BRS on age-stratified trends of obesity-related gastrointestinal cancers (OGCs) including that of CRC. METHODS: We queried the 2006-2013 National Inpatient Sample (NIS), the largest publicly available all-payer data repository, to identify patients who underwent resections for OGCs. We investigated patients with morbid obesity (body mass index ≥ 40 kg/m2) and those with prior BRS. In a separate analysis, we also looked at non-BRS/non-obese individuals. We divided OGCs into two groups: CRC and non-CRC OGCs (esophageal, gastric, liver, gallbladder and pancreatic cancers combined). Joinpoint regression analysis was used to calculate the average annual percent change (AAPC) in patients undergoing cancers resections across age groups (age < 50 and ≥ 50 years old). RESULTS: We identified 28,041 patients with morbid obesity and 2,238 patients with a prior BRS who had resections for OGCs in 2006-2013. BRS patients were younger, with more females and fewer comorbidities (Table 1). The yearly number of morbidly obese and BRS patients who underwent CRC resections concurrently increased across all age groups (Figures 1 and 2). When stratified by age, the steepest rise in CRC was observed in BRS patients <50 years of age (AAPC +18.7%, P < 0.001). Conversely, non-CRC OGCs did not go up after BRS, while number of morbidly obese patients undergoing non-CRC OGCs increased in patients ≥50 years of age (AAPC +18.1%, P = 0.004). Finally, in a supplementary analysis, the number of non-BRS/non-obese patients with CRC resections, decreased in 2006-2013 [AAPC -3.3 (P = 0.002) and -3.4 (P < 0.001) for patients < and ≥50 respectively]. CONCLUSION: Our results identify a recent paradoxical increase in CRC resections after bariatric surgery, most pronounced for early-age onset CRC. Other obesity-related gastrointestinal cancers did not increase after bariatric surgery, suggesting a low probability of referral bias leading to our findings. Further research is warranted to elaborate on these trends and provide biological context.