Risk factors associated with rectal neuroendocrine tumors: a cross-sectional study.

BACKGROUND The incidence of rectal neuroendocrine tumors (NET) has been increasing since the implementation of the screening colonoscopy. However, very little is known about risk factors associated with rectal NETs. We examined the prevalence of and the risk factors for rectal NETs in a Korean population. METHODS A cross-sectional study was performed on 62,171 Koreans who underwent screening colonoscopy. The clinical characteristics and serum biochemical parameters of subjects with rectal NET were compared with those of subjects without rectal NET using multivariate logistic regression. RESULTS Of a total of 57,819 participants, 101 [OR, 0.17%; 95% confidence interval (CI), 0.14-0.20] had a rectal NET. Young age (<50 years; OR, 2.09; 95% CI, 1.06-4.15), male gender (OR, 1.92; 95% CI, 1.15-3.20), alcohol drinking [adjusted OR (AOR), 1.56; 95% CI, 1.01-2.42], and a low high-density lipoprotein-cholesterol (HDL-C) level (AOR, 1.85; 95% CI, 1.10-3.11) were independent risk factors for rectal NETs. Cigarette smoking, fatty liver, metabolic syndrome, higher triglyceride level (≥150 mg/dL), and higher homeostasis model assessment of insulin resistance (≥2.5) were not independently associated with rectal NETs, although these factors were more common in individuals with rectal NETs in the univariate analysis. CONCLUSIONS Young age (<50 years), male gender, alcohol drinking, and a low HDL-C level were risk factors for rectal NETs. Our results suggest that gender, behavioral factors, and dyslipidemia may affect the risk for developing rectal NETs. IMPACT The findings of this study contribute to a better understanding of the influence of gender, behavioral factors, and dyslipidemia in developing rectal NETs.