Background & aims: Nonalcoholic fatty liver disease (NAFLD) is known to increase the risk of adenomatous colonic polyps. However, the role of screening colonoscopy in patients with biopsy-proven NAFLD in detecting advanced colorectal neoplasm is not clearly evidence-based. Therefore, we investigated whether the histological severity of NAFLD is associated with advanced colorectal neoplasm.
Methods: This study included patients ≥18 years old who underwent screening colonoscopy between 2013 and 2018 within a biopsy-evaluated prospective NAFLD cohort. Advanced colorectal neoplasm was defined as an adenomatous polyp greater than 10 mm in diameter and/or with villous histology and/or with high-grade dysplasia or adenocarcinoma.
Results: Among the 476 patients with clinically suspected NAFLD, 379 patients were diagnosed with biopsy-proven NAFLD and 97 patients had no evidence of NAFLD histologically, who were analyzed as healthy controls. The prevalence of advanced colorectal neoplasm was 11.1% (n = 53). Patients with advanced colorectal neoplasm had higher grade of steatosis (P = 0.004) and higher stage of hepatic fibrosis (P = 0.044) than those with normal colonoscopic findings or low-grade adenomatous polyp. Multivariable logistic regression analysis revealed that the presence of nonalcoholic steatohepatitis (NASH) was an independent risk factor for both colorectal polyp (odds ratio [OR], 2.08; 95% confidential interval [CI], 1.12-3.86; P = 0.020) and advanced colorectal neoplasm (OR, 2.81; 95% CI, 1.01-7.87; P = 0.049).
Conclusions: The presence of biopsy-proven NASH was significantly associated with an increased risk of advanced colorectal neoplasm among patients with NAFLD. This finding may alert physicians to conduct screening colonoscopy in patients with NASH to detect advanced colorectal neoplasm early.
Keywords: colonoscopy; colorectal cancer; liver fibrosis; non-alcoholic fatty liver disease.
© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.