A new staging system for hepatocellular carcinoma associated with portal vein tumor thrombus

Background:A new staging system for patients with hepatocellular carcinoma(HCC)associated with portal vein tumor thrombus(PVTT)was developed by incorporating the good points of the BCLC classification of HCC,and by improving on the currently existing classifications of HCC associated with PVTT.Methods:Univariate and multivariate analysis with Waldχ2 test were used to determinate the clinical prognostic factors for overall survival(OS)in patients with HCC and PVTT in the training cohort.Then the conditional inference trees analysis was applied to establish a new staging system.Results:A training cohort of 2,179 patients from the Eastern Hepatobiliary Surgery Hospital and a validation cohort of 1,550 patients from four major liver centers in China were enrolled into establishing and validating a new staging system.The system was established by incorporating liver function,general health status,tumor resectability,extrahepatic metastasis and extent of PVTT.This staging system had a good discriminatory ability to separate patients into different stages and substages.The median OS for the two cohorts were 57.1(37.2-76.9),12.1(11.0-13.2),5.7(5.1-6.2),4.0(3.3-4.6)and 2.5(1.7-3.3)months for the stages 0 to IV,respectively(P<0.001)in the training cohort.The corresponding figures for the validation cohort were 6.4(4.9-7.9),2.8(1.3-4.4),10.8(9.3-12.4),and 1.5(1.3-1.7)months for the stages II to IV,respectively(P<0.001).The mean survival for stage 0 to 1 were 37.6(35.9-39.2)and 30.4(27.4-33.4),respectively(P<0.001).Conclusions:A new staging system was established which provided a good discriminatory ability to separate patients into different stages and substages after treatment.It can be used to supplement the other HCC staging systems.