Increased Cancer Risk in Autoimmune Hepatitis: A Danish Nationwide Cohort Study.

Introduction Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease and as such may increase the risk of cancer. We examined cancer risks in a nationwide cohort of patients with AIH. Methods This study was based on nationwide Danish healthcare registries. We identified all persons diagnosed with AIH between 1994 and 2018. We included 1805 patients with AIH and 16,617 age- and sex-matched population controls. We estimated cumulative risks of cancers and risk ratios (RRs) between patients and controls. Within the cohort of patients with AIH, we examined the impact of immunosuppressive treatment (IST) and cirrhosis on cancer risks. Results The 10-year risk of any cancer was 13.6% (95% confidence interval [CI] 11.7-15.6) in patients with AIH with an RR of 1.5 (95% CI 1.3-1.7) compared with controls. Patients with AIH had a 10-year risk of 0.5% (95% CI 0.2-1.1) for hepatocellular carcinoma. The 10-year risk was 1.6% (95% CI 1.0-2.5) for colorectal cancer (RR: 2.1 [95% CI 1.3-3.5]) and 4.0% (95% CI 3.0-5.3) for nonmelanoma skin cancer (RR: 1.8 [95% CI 1.3-2.5]). Among patients with AIH, the risk of cancer was higher for those with cirrhosis (hazard ratio: 1.3 [95% CI 1.0-1.7]), and it also increased 1.05-fold (95% CI 1.0-1.1) for every year the patient was on IST. Discussion AIH was associated with a 1.5-fold increased 10-year risk of cancer compared with age- and sex-matched controls. Among patients with AIH, the risk of cancer was higher for those with cirrhosis, and it also increased slightly with longer duration of IST.