Hepatocellular carcinoma in primary sclerosing cholangitis and primary biliary cholangitis: a clinical and pathological study in an uncommon but emerging setting

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are biliary tract pathologies with increased risk of HCC, although HCC is more commonly associated with viral hepatitis and steatohepatitis. HCC risk stratification in PBC/PSC populations may help select patients for surveillance. We hypothesized that metabolic syndrome associated diagnoses and co-morbid nonalcoholic fatty liver disease (NAFLD) may be risk factors for HCC in patients with PBC and PSC. We undertook a multi-institutional case control study of PSC (19 cases, 38 controls) and PBC (39 cases and controls) patients with advanced fibrosis, matched for known HCC risk factors of age and sex, who had native liver explant or resection specimens. In the PSC population, HCC risk was significantly associated with multiple metabolic syndrome associated diagnoses (OR 13, p = 0.02), hyperlipidemia (OR 29, p = 0.03), and obesity (OR 6.8, p = 0.01). In the PBC cohort, only type 2 diabetes was a risk factor for HCC (OR 4.7, p = 0.03). In the PSC cohort, thick fibrous septae were associated with HCC risk (OR 3.4, p = 0.04). No other pathologic features of the nonneoplastic liver were significantly associated with HCC, including features of NAFLD such as macrovesicular steatosis, pericellular fibrosis, and steatohepatitis. Metabolic syndrome associated diagnoses, specifically type 2 diabetes among PBC patients, is associated with HCC risk in patients with biliary type cirrhosis. However, we found no evidence that HCC risk is related to co-morbid NAFLD, indicating a likely distinct mechanism of metabolic syndrome-associated carcinogenesis in these populations.