Assessment of the discriminating value of the 8th AJCC stage grouping for hepatocellular carcinoma

Background: This study seeks to validate the discriminating value of the 8th edition of the American Joint Committee on Cancer (AJCC) staging system for Hepatocellular carcinoma (HCC) amongst patients registered within the surveillance, epidemiology and end results (SEER) database. Methods: Through SEER* Stat program, SEER database (2010-2013) was queried and 8th AJCC stage groups were reconstructed. Overall and cancer-specific survival analyses according to both 7th and 8th editions were conducted through Kaplan-Meier analysis/log-rank testing and multivariate analysis was conducted through a Cox proportional model. Results: For overall and cancer-specific survival assessment according to the 8th edition, P values for pair wise comparisons among different stages were significant (<0.001) in all comparisons except for stage IB vs. II/stage IIIB vs. stage IVA. A modified AJCC 8th staging system was suggested through collapsing stages IB/II into one stage and stages IIIB/IVA into one stage. Overall and cancer-specific survivals were compared according to this modified system and pair wise P value was significant in all comparisons (P < 0.001). Conclusion: There is a minimal improvement in discriminating value for the 8th edition compared to the 7th edition; however, notable overlap in outcomes is still observed between stages IB/II and IIIB/IVA. A modified AJCC 8th system collapsing these overlapping stages may be more clinically relevant.