Comparison between the fifth and sixth editions of the AJCC/UICC TNM staging systems for hepatocellular carcinoma: multicentric study on 393 cirrhotic resected patients

Aims To compare the prognostic efficacy of the 5th and 6th edition of the TNM staging system for HCC. Methods We retrospectively applied the old and the new systems to 393 resected patients, comparing the efficacy of both in prognostic evaluation. Results The 1-, 3- and 5-year overall survival rates were 89.7, 71.1 and 56.3%, respectively. The 1-, 3- and 5-year disease-free survival rates were 79.4, 54.6 and 39.4%, respectively. Among the factors evaluated, Childʹs grade B and C (p=0.001) and presence of multiple nodules (p=0.01) were found to be related either to a worse long-term survival or to a worse disease-free survival. Stratifying patient survivals according to the old TNM system, we found significant differences only between stages II and IIIA (p=0.001); otherwise stages I and II (p=0.9) as well as stages IIIA and IVA (p=0.9) showed similar survival rates. Analysing the new TNM system, we found a more homogeneous staging stratification, with significant differences both between stage I and II (p=0.02) and between stage II and IIIA (p=0.05). Conclusions In the present multicentric study, long term overall and disease-free survival after liver resection for HCC was strongly affected by the number of tumours and the underlying liver disease. Our results suggest that the new classification appears to achieve an accurate stratification of patients, simpler than the previous edition, as well as a more reliable comparative analysis of outcome after hepatic resection for HCC.