Extrahepatic malignancies in metabolic dysfunction‐associated fatty liver disease: A nationwide cohort study

Background and Aims Metabolic dysfunction‐associated fatty liver disease (MAFLD) encompasses heterogeneous fatty liver diseases associated with metabolic disorders. We aimed to evaluate the association between MAFLD and extrahepatic malignancies based on MAFLD subtypes. Methods This nationwide cohort study included 9 298 497 patients who participated in a health‐screening programme of the National Health Insurance Service of Korea in 2009. Patients were further classified into four subgroups: non‐MAFLD, diabetes mellitus (DM)‐MAFLD, overweight/obese‐MAFLD and lean‐MAFLD. The primary outcome was the development of any primary extrahepatic malignancy, while death, decompensated liver cirrhosis and liver transplantation were considered competing events. The secondary outcomes included all‐cause and extrahepatic malignancy‐related mortality. Results In total, 2 500 080 patients were diagnosed with MAFLD. During a median follow‐up of 10.3 years, 447 880 patients (6.0%) with extrahepatic malignancies were identified. The DM‐MAFLD (adjusted subdistribution hazard ratio [aSHR] = 1.13; 95% confidence interval [CI] = 1.11–1.14; p