ABSTRACT
This chapter reviews the current evidence and potential mechanisms underpinning observed associations between nonalcoholic fatty liver disease (NAFLD) and both hepatic and extrahepatic cancers (with a focus on cholangiocarcinoma, colorectal, esophageal, gastric, pancreatic, genitourinary, breast, uterine, lung and hematologic cancers). While the precise mechanisms linking NAFLD to carcinogenesis are largely undefined, NAFLD is viewed as the hepatic manifestation of metabolic syndrome, and a body of evidence indicates an increased risk of cancer—particularly gastrointestinal and hepatic cancers—in patients with metabolic syndrome. In parallel with the growing epidemics of obesity and type 2 diabetes, NAFLD is a growing cause of hepatocellular carcinoma in the US. However, other studies have found that liver metastases of colorectal cancer (CRC) arise less frequently in the setting of NAFLD; thus prospective research is still needed in populations with well-phenotyped NAFLD, which also carefully distinguishes between synchronous and metachronous CRC metastasis.
