Evaluation of the aMAP score for hepatocellular carcinoma surveillance: a realistic opportunity to risk stratify

Abstract

Background and aimsThe aMAP score is a model that predicts risk of hepatocellular carcinoma (HCC) development in patients with chronic hepatitis. Its performance in a ‘real world’ surveillance setting has not yet been ascertained.Patients and methodsWe had access to a cohort of 3473 individuals enrolled in a rigorously implemented and prospectively accrued surveillance programme (patients undergoing regular ultrasound and biomarker examination between 1998 and 2021). During this period 445 had HCC detected. Of these, 77.8% had early stage disease (within Milan criteria), permitting potentially curative therapy to be implemented in nearly 70% of cases. We applied the recently developed aMAP score to classify patients according to their initial aMAP score in to low, medium and high-risk groups as proposed in the original publication. The performance of the aMAP score was assessed according to the concordance-index and calibration (i.e. agreement between observed and predicted risk). Allowance was made for competing causes of death.ResultsThe aMAP score achieved an overall C-index of 0.81 (95% CI: 0.79–0.82) consistent with the initial report and was unaffected by allowance for competing causes of death. Sub-group analysis showed that the results did not change significantly according to gender, or aetiology. However, aMAP discrimination was greater for younger individuals (versus older individuals), and also for individuals without cirrhosis. The HCC incidence rate was 0.98, 7.05 and 29.1 events per 1000 person-years in the low-, moderate- and high-risk aMAP groups, respectively.ConclusionsThe results from this ‘real-world’ cohort demonstrate that risk stratification is a realistic prospect and that identification of a subgroup of chronic liver disease patients who have a very low risk of HCC is feasible.