The prognosis prediction value of the 8th edition of the American Joint Committee on Cancer Staging System in patients with resectable hepatocellular carcinoma

Objective To compare the prognosis prediction value of the 8th edition with the 7th edition of the American Joint Committee on Cancer Staging System in patients with resectable hepatocellular carcinoma (HCC). Methods A total of 311 HCC patients after hepatectomy were retrospectively analysed. Patients were staged according to both the 7th edition (TNM-7) and 8th edition (TNM-8) AJCC TNM staging criteria. The survival rates were estimated using Kaplan-Meier methods. Multivariate analysis was assessed by Cox proportional hazards regression analysis. The predictive ability of staging systems was evaluated by receiver operating characteristic curve (ROC) and area under curve (AUC). Results When stratified according to the TNM-7 system, the overall survival(OS) of stage T1 was higher than that of stage T2, stage T2 higher than stage T3a, however, the 5-year OS rates of stage T4 (16.7%) was higher than those of stage T3a (14.3%) and T3b(10.9%). The difference in survival was significant between stages T1 and stage T3a, T3b, T4 (all P<0.05), and that between stages T2 and stage T3b, T4 (all P<0.05). When stratified according to the TNM-8 system, the survival rates decreased as the T stage going high. OS rates vary significantly between stagesT1a and stageT3, T4 (P=0.004, 0.001), between stage T1b and stage T3, T4 (both P<0.001), and between stage T2 and stage T4 (P=0.009). The difference in disease free survival (DFS) rates was significant between stages T1a, T1b, T2 and stage T3, T4 (all P<0.01). Finally, the area under ROC of TNM-8 is bigger than that of TNM-7. Conclusions Compared with TNM-7 staging, new TNM-8 staging can predict more accurately the prognosis of patients with resectable hepatocellular carcinoma. Key words: Carcinoma, hepatocellular; Neoplasm staging; Prognosis