Background: Risk of hepatocellular carcinoma (HCC) may be difficult to determine in the clinical setting.
Aim: Develop a scoring system to forecast HCC risk among patients with chronic hepatitis C.
Methods: Using data from the Chronic Hepatitis Cohort Study collected during 2005-2014, we derived HCC risk scores for males and females using an extended Cox model with aspartate aminotransferase-to-platelet ratio index (APRI) as a time-dependent variables and mean Kaplan-Meier survival functions from patient data at two study sites, and used data collected at two separate sites for external validation. For model calibration, we used the Greenwood-Nam-D'Agostino goodness-of-fit statistic to examine differences between predicted and observed risk.
Results: Of 12,469 patients (1628 with a history of sustained viral response [SVR]), 504 developed HCC; median follow-up was 6 years. Final predictors in the model included age, alcohol abuse, interferon-based treatment response, and APRI. Point values, ranging from -3 to 14 (males) and -3 to 12 (females), were established using hazard ratios of the predictors aligned with 1-, 3-, and 5-year Kaplan-Meier survival probabilities of HCC. Discriminatory capacity was high (c-index 0.82 males and 0.84 females) and external calibration demonstrated no differences between predicted and observed HCC risk for 1-, 3-, and 5-year forecasts among males (all p values >0.97) and for 3- and 5-year risk among females (all p values >0.87).
Conclusion: This scoring system, based on age, alcohol abuse history, treatment response, and APRI, can be used to forecast up to a 5-year risk of HCC among hepatitis C patients before and after SVR.
Keywords: Hepatitis C; Hepatocellular carcinoma; Prediction; Risk; Score.