Controlled attenuation parameter value and the risk of hepatocellular carcinoma in chronic hepatitis B patients under antiviral therapy

Background: Controlled attenuation parameter (CAP) can evaluate hepatic steatosis in patients with chronic hepatitis B (CHB). However, prognostic implications of CAP value remain unclear. We evaluated the association between CAP and the risk of hepatocellular carcinoma (HCC) in patients with CHB under antiviral therapy and maintained virologic response. Methods: A total of 1823 CHB patients who were taking nucleos(t)ide analogue and showing suppressed hepatitis B virus replication were analyzed. The primary outcome was incident HCC during follow-up. Patients were grouped into those with and without advanced chronic liver disease (ACLD) (liver stiffness measurement cutoff: 10 kPa), and those with and without hepatic steatosis (CAP cutoff: 222 dB/m). Results: During 6.4 years of follow-up, 127 patients (7.0%) newly developed HCC. Among patients with ACLD (n = 382), the cumulative HCC incidence rate was lower for those with CAP ≥ 222 (11.0% at 5 years) than those with CAP < 222 (24.0% at 5 years, p = 0.002), and was an independent factor associated with HCC. When CAP value was further stratified, the cumulative HCC incidence rate decreased in dose-dependent manner according to an increase in CAP value (24.0%, 13.9%, 12.8% and 6.0% at 5 years for those with CAP < 222, 222–246, 247–273 and ≥ 274, respectively). Among patients without ACLD (n = 1441), there was no significance difference in HCC risk according to CAP value (HCC incidence rate: 3.3% and 4.0% at 5 years for those with CAP < 222 and CAP ≥ 222, p = 0.20). Conclusions: Among CHB patients under antiviral therapy showing suppressed HBV replication, low CAP value predicted higher risk for HCC among ACLD patients, indicating that CAP value has a prognostic implication in this population.