A simplified American Joint Committee on Cancer (AJCC) TNM staging system for hepatocellular carcinoma (HCC) (the 6th edition) was proposed in 2002. In this study, we validated the prognostic value of the staging system in a patient cohort undergoing hepatic resection with longterm followup.
From a prospective database, the study cohort consisted of 440 patients who underwent curative hepatic resection for HCC between July 1991 and January 1999. Median followup time was 66 months. Multivariate analysis was performed to identify the independent prognostic factors related to postoperative survival. Patients were staged according to both the 5th edition (TNM-5) and 6th edition (TNM-6) AJCC TNM staging criteria.
The independent prognostic factors included major vascular invasion, microvascular invasion, surgical margin < 1 cm, indocyanine green retention rate at 15 minutes > 10%, multiple tumors, tumor rupture, male, and serum aspartate aminotransferase > 90 U/L. The breakdown by TNM-5 staging: I, 27 (6.1%); II, 108 (24.5%); III, 218 (49.5%); and IVA, 87 (19.8%) and by TNM-6 staging: I, 120 (27.3%); II, 170 (38.6%); and III, 150 (34.1%). When stratified according to the TNM-5 system, difference in survival was notable between stages II and IIIA (p < 0.001), between stages IIIA and IVA (p < 0.001), but not between stages I and II (p > 0.05). When stratified according to the TNM-6 system, difference in survival was considerable between stages I and II (p < 0.01), stages II and III (p < 0.001), and stages I and III (p < 0.001).
Overall, the TNM-6 staging system appears to provide a reliable prognostic classification of HCC patients and is simpler to use than the TNM-5 staging system.