282 Risk Factors for Colorectal Cancer in Patients Under 50: A Retrospective Study

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INTRODUCTION: Colorectal cancer (CRC) incidence and mortality rates are rising in patients under age 50 for uncertain reasons. This study aims to identify risk factors and tumor characteristics of younger CRC patients aged 19–49 (Y-CRC), compared to a control group of CRC patients aged 50–60 (CRC-50+). METHODS: From a clinical and administrative database at a single institution, we identified patients with an initial CRC diagnosis between 2010–2012. Only histologically confirmed primary colon adenocarcinomas were included. Clinical and demographic characteristics were extracted via chart review. Bivariate and multivariable analyses were performed to compare Y-CRC and CRC-50+ groups. RESULTS: A total of 190 patients met our criteria (100 CRC = 50+, 90 Y-CRC). Most patients were white (123 patients, 64.7%), and 49 were black (25.8%). There were 90 female patients (47.4%). The average body mass index (BMI) was 27.1 kg/m2. 64 patients (33.7%) were current smokers. Family history of CRC or polyps was noted in 54 patients (18.4%). History of inflammatory bowel disease (IBD) was present in 11 patients (5.8%). The 12 patients (6.3%) with CRC-predisposing genetic syndromes were excluded from case-control analysis. We found no differences in BMI between groups (P = 0.8). There was a substantially higher proportion of Hispanic patients in Y-CRC group versus CRC-50+ group (13.9% vs. 0%, P < 0.01). Diabetes was less common in Y-CRC than CRC-50+ (7.6% vs. 18.2%, P = 0.04). There was no statistically significant difference between groups in smoking history or family history of CRC/polyps. Although IBD was more common in Y-CRC (8.9% vs. 4.0%), the difference was not statistically significant (P = 0.2). Rectal cancers were slightly more common in Y-CRC (55.1% vs. 47.5%), but this was not statistically significant. Y-CRC patients were more likely to present at later stages and with synchronous lesions, compared to CRC-50+ cases. On multivariable analysis, Y-CRC was associated with Hispanic ethnicity and inversely associated with diabetes, after controlling for other factors (Table 2). CONCLUSION: Aside from a higher proportion of Hispanic ethnicity and lower proportion of diabetes among Y-CRC cases, the Y-CRC and CRC-50+ groups were comparable. We found no evidence of an association between family history, obesity or smoking with Y-CRC cases. Further work is needed to explore these and other potential risk factors for Y-CRC.