Cancer Risk in Patients with Autoimmune Hepatitis: A Nationwide Population-Based Cohort Study with Histopathology.

We aimed to determine the risk of incident cancer in autoimmune hepatitis (AIH) compared to the general population and siblings. AIH was defined by the presence of a medical diagnosis of AIH and a liver biopsy in a nationwide Swedish population-based cohort study. We identified 5,268 adults with AIH diagnosed 1969-2016 and 22,996 matched general population reference individuals and 4,170 sibling comparators. Using Cox regression, hazard ratios (HRs) were determined for any incident cancer and sub-types determined from the Swedish Cancer Register. During follow-up, a cancer diagnosis was made in 1,119 individuals with AIH (17.2/1000 person-years) and 4,450 reference individuals (12.0/1000 person-years). This corresponded to an HR of 1.53 (95%CI: 1.42,1.66). Cancer risk was highest in those with cirrhosis. There was a 29.18-fold increased risk of hepatocellular carcinoma (HCC) (95%CI, 17.52,48.61). The annual incidence risk of HCC in individuals with AIH who had cirrhosis was 1.1% per year. AIH was also linked to non-melanoma skin cancer (HR=2.69) and lymphoma (HR=1.89). Sibling analyses yielded similar risk estimates for any cancer (HR=1.84) and HCC (HR=23.10). AIH is associated with an increased risk of any cancer, in particular, HCC and extra-hepatic malignancies. The highest risk for cancer, especially HCC, is in patients with cirrhosis.