The association between nonalcoholic fatty liver disease and risk of colorectal adenoma and cancer incident and recurrence: a meta-analysis of observational studies

Background & aim: Lifestyle modification plays a key role in nonalcoholic fatty liver disease (NAFLD) and colorectal adenoma and/or cancer (CRA/CRC) development. However, the association between NAFLD and the risk of CRA/CRC has not been carefully evaluated. Methods: In this meta-analysis, we assessed 21 eligible studies including 124,206 participants to determine the association between NAFLD and the risk of incident and recurrent CRA/CRC. Results: NAFLD presence was associated with an increased risk of any incident CRA (aOR: 1.30, 95% CI: 1.19-1.43) and advanced incident CRA/CRC (aOR: 1.57, 95% CI: 1.21-2.04). The severity of NAFLD affected this correlation: compared to mild and/or moderate NAFLD, severe NAFLD was associated with an increased risk of incident CRA/CRC (aOR: 2.19, 95% CI: 1.33-3.60). Although pooled cOR revealed that NAFLD was associated with an increased risk of recurrent CRA/CRC (cOR = 1.73; 95% CI: 1.12-2.68), after adjustment for confounding factors, NAFLD had less correlation with the risk of recurrent CRA/CRC (aOR: 1.81, 95% CI: 0.70-4.65). Conclusions: The presence and severity of NAFLD are associated with an increased risk of incident CRA/CRC. However, there is insufficient evidence to indicate that NAFLD is associated with an increased risk of recurrent CRA/CRC.