A new prognostic model for hepatocellular carcinoma based on total tumor volume: the Taipei Integrated Scoring System

Abstract

Background & aims: The currently used staging systems for hepatocellular carcinoma (HCC) are not satisfactory. The optimal prognostic model for HCC is still under intense debate. This study aimed to propose a new staging system for HCC based on total tumor volume (TTV) and to compare it with the currently used systems.

Methods: A total of 2030 HCC patients undergoing different treatment strategies were retrospectively analyzed. TTV was defined as the sum of the volume of each tumor [(4/3)x3.14x(radius of tumor in cm)(3)]. The discriminatory ability of the TTV-based staging system and the four current systems, including the Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program (CLIP), Japan Integrated Staging system, and Tokyo system, was examined by comparing the Akaike information criterion (AIC) using the Cox proportional hazards model.

Results: A higher TTV correlated well with the decreased survival in HCC patients (p<0.001). Among the 12 TTV-based staging systems, the TTV-Child-Turcotte-Pugh (CTP)-alpha-fetoprotein (AFP) combination provided the lowest AIC value. The TTV-CTP-AFP model consistently showed a better prognostic ability in comparison to the current four staging systems. In 936 HCC patients receiving curative treatment, the TTV-CTP-AFP model provided the second best predictive accuracy following the CLIP score. Alternatively, in 1094 patients undergoing non-curative treatment, the TTV-CTP-AFP model exhibited the smallest AIC value.

Conclusions: TTV may be a feasible tumoral prognostic predictor for HCC. In this single-hospital study that included patients with early to advanced cancer stages, the TTV-CTP-AFP model provides the best prognostic ability among 12 TTV-based and currently used staging systems.