Comparing predicted probability of hepatocellular carcinoma in cirrhosis patients to the general population: an opportunity to improve risk communication?

INTRODUCTION: Risk scores estimating a patient's probability of a hepatocellular carcinoma(HCC) diagnosis are abundant but are difficult to interpret in isolation. We compared the predicted HCC probability for individuals with cirrhosis and cured hepatitis C with the general population (GP).

METHODS: All patients with cirrhosis achieving sustained viral response (SVR) in Scotland by April 2018 were included (N = 1,803). The predicted 3-yearprobability of HCC at time of SVR achievement was determined using the aMAP prognostic model. GP data on the total number of incident HCCs in Scotland, stratified by demographics, were obtained from Public Health Scotland. Predicted HCC risk of cirrhosis SVR patients was compared with GP incidence using 2 metrics: (i) incidence ratio: i.e., 3-year predicted probability for a given patient divided by the 3-year probability in GP for the equivalent demographic group and (ii) absolute risk difference: the 3-year predicted probability minus the 3-year probability in the GP.

RESULTS: The mean predicted 3-year HCC probability among cirrhosis SVR patients was3.64% (range: 0.012%–36.12%). Conversely, the 3-year HCC probability in the GP was much lower, ranging from <0.0001% to 0.25% depending on demographics. The mean incidence ratio was 410, ranging from 5 to >10,000. The mean absolute risk difference was 3.61%, ranging from 0.012% to 35.9%. An online HCC-GP comparison calculator for use by patients/clinicians is available at https://thrive-svr.shinyapps.io/RShiny/.

DISCUSSION: Comparing a patient's predicted HCC probability with the GP is feasible and may help clinicians communicate risk information and encourage screening uptake.