Prognostic sub-classification of intermediate-stage hepatocellular carcinoma: a multicenter cohort study with propensity score analysis.

There is significant heterogeneity in the clinicopathological characteristics of intermediate hepatocellular carcinoma (IHCC). This also translates to treatment as transarterial chemoembolization (TACE) is used as first-line therapy for patients with IHCC; however, in Asia liver resection (LR) is preferred. Prognostic tools are required to help guide clinicians in deciding treatment options. This study evaluates the prognostic impact of the Intermediate Stage Score (ISS) on overall survival (OS) in a large, multicenter cohort study of patients with IHCC treated with TACE or surgery LR. Consecutive patients from centers in Japan, Korea, Italy and the United Kingdom who underwent TACE or LR between 2001 and 2015 were enrolled. Propensity score (PS) adjustment was used to remove residual confounding and applied to LR (n = 162) and TACE (n = 449) to determine the prognostic significance of ISS. Among 611 patients, 75 % were men and 25 % women, with a mean age of 70 years. ISS is a valid prognostic tool in the BCLC-B population with a median OS ISS 1-51, 2-38.3, 3-24.3, 4-15.6, 5-16 months (p < 0.0001). ISS was analyzed within each treatment modality, and this was a valid prognostic score among those treated with TACE and LR (p < 0.001 vs. p = 0.008). In the PS-adjusted model, ISS retained its prognostic utility in TACE and LR groups (p < 0.001 vs. p = 0.007). ISS optimizes prognostic prediction in IHCC, reducing clinical heterogeneity, and is a useful tool for patients treated for TACE or LR.