The comparative analysis of nasopharyngeal carcinoma among Chinese 1992, 2008 and union for international cancer control (UICC) 2010 staging systems

Abstract

Objective To compare the agreement among Chinese 1992, 2008 and UICC 2010 staging systems of nasopharyngeal carcinoma (NPC) and evaluate their predictive value of radiotherapeutic prognosis.Methods 347 NPC patients without distant metastasis treated in our hospital from 2000 to 2005 were retrospectively analyzed.Every patient was categorized into T, N, and clinical stage by Chinese 1992, 2008 and UICC 2010 staging systems, respectively.Kappa value was used to evaluate the agreement among three systems.Kaplan-Meier method was used to analyze the 5-year overall survival (OS), local-free survival (LFS) and distant metastasis-free survival (DMFS), the difference between subgroup was tested by Logrank.Results The agreement of clinical stage, T and N stage between Chinese 2008 and UICC 2010 staging system was better than that of them compared to 1992 staging system, Kappa value were 0.700、0.881 and 0.722.The agreement of T stage was better than N and clinical stage among these three staging system.The difference of OS between stageⅢ and stage Ⅳ was significant in Chinese 2008 and UICC 2010 staging system (χ2=4.48,P=0.034;χ2=8.88,P=0.003), and with no different in 1992 staging system (χ2=0.40,P=0.526).There was no significant difference of LFS between T1 and T2,T2 and T3,T3 and T4 in all staging systems (χ2=1.85,0.53,0.50,P=0.174,0.467,0.479;χ2=1.25,2.10,1.99,P=0.264,0.148,0.159;χ2=0.77,0.60,0.87, P=0.381,0.441,0.350).There were no significant differencesin 1992 staging system, while there was significant differences of DMFS between N1 and N2, N2 and N3 in 2008 stage system, N1 and N2 in UICC 2010 stage system.Conclusions The predictive value of Chinese 2008 and UICC 2010 staging system for prognosis were similar, and were better than that of 1992 staging system in NPC. Key words: Nasopharyngeal neoplasm/radiotherapy; Prognosis; Stage system