Association between non-alcoholic fatty liver disease and cancer incidence rate.

BACKGROUND & AIMS Little is known about the association between non-alcoholic fatty liver disease (NAFLD) and cancer development. This study investigated the cancer incidence rates in NAFLD and analysed the association between NAFLD and cancer development. METHODS This historical cohort study included subjects who were followed up for >1 year after having a heath checkup at a tertiary hospital in Korea from September 1, 2004 to December 31, 2005. NAFLD was diagnosed by ultrasonographic detection of hepatic steatosis in the absence of other known liver disease, including alcoholic or viral hepatitis. Cox proportional hazards regression model was conducted to assess the association between NAFLD and cancer development. RESULTS Of 25,947 subjects, 8,721 (33.6%) had NAFLD. During the total follow-up of 164,671 person-years (median 7.5 years), the cancer incidence rate of the NAFLD group was higher than that of the non-NAFLD group (782.9 vs. 592.8 per 100,000 person-years; hazard ratio [HR] 1.32; 95% confidence interval [CI] 1.17-1.49; p <0.001). When demographic and metabolic factors were adjusted for, NAFLD showed a strong association with three cancers: hepatocellular carcinoma ([HCC]; HR 16.73; 95% CI 2.09-133.85; p = 0.008), colorectal cancer in males (HR 2.01; 95% CI 1.10-3.68; p = 0.02), and breast cancer in females (HR 1.92; 95% CI 1.15-3.20; p = 0.01). A high NAFLD fibrosis score (NFS) and a high fibrosis-4 (FIB-4) score were associated with the development of all cancers and HCC. CONCLUSION NAFLD was associated with the development of HCC, colorectal cancer in males, and breast cancer in females. A high NFS and a high FIB-4 score showed a strong association with the development of all cancers and HCC. LAY SUMMARY Non-alcoholic fatty liver disease (NAFLD) is associated with developing hepatocellular carcinoma (HCC). There have been limited data on the association between NAFLD and extrahepatic cancers. This study demonstrated that patients with NAFLD showed a higher association with the development of HCC, colorectal cancer in males, and breast cancer in females. A high NAFLD fibrosis score and a high fibrosis-4 score showed a strong association with the development of all cancers and HCC.