The Comparative Analysis Of Radiotherapeutic Prognosis Of Nasopharyngeal Carcinoma According To Chinese 1992, 2008 And UICC2010 Staging Systems

Objective Currently, there are no uniform stage classifications for nasopharyngeal carcinoma (NPC) in the world. In 2008, china developed the 2008 staging system based on the 1992 staging system. At the same time, union for international cancer control (UICC) also published the latest version of the NPC staging system in 2010. However, the comparative analysis among these staging systems is also inadequate. This is not conducive to aid in treatment planning, indicate the prognosis, and aid in analysis and information exchange among different treatment centers for clinical studies pertaining to NPC. We performed a retrospective review of data from 347 biopsy-proven nonmetastatic nasopharyngeal carcinoma patients. To compare the agreement among Chinese 1992, 2008 and UICC 2010 staging systems of nasopharyngeal carcinoma(NPC), and to evaluate their predictive value of radiotherapeutic prognosis.Methods Clinical data of 347 NPC patients without distant metastasis 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. The overall survival (OS), local-free survival (LFS) and distant metastasis-free survival (DMFS) according to clinical, T and N stage were calculated by Kaplan-Meier, and the significance was tested by log-rank.Results The agreement of T, N and clinical stage between Chinese 2008 and UICC 2010 staging system was better than one of them compared to 1992 staging system. Kappa was 0.700, 0.881 and 0.722, respectively. The agreement of T stage in Chinese 2008 and UICC 2010 staging system compared to 1992 staging system was better than N and clinical stage. Kappa was 0.877 and 0.761, 0.485 and 0.531, 0.570 and 0.548, respectively. The distributions of OS according to clinical stage of Chinese 2008 and UICC 2010 staging system were better than these of 1992 staging system(χ²=36.30, P=0.000;χ²=37.73, P=0.000;χ²=33.19, P=0.000). The curves betweenⅢandⅣstage In the 1992 staging system were overlapped(χ²=0.401,P=0.526). There was no significant difference of LFS between T1 and T2, T2 and T3, T3 and T4 in all staging system(χ²=0.529,0.502,1.849,P=0.467,0.479,0.174�'�χ²=2.096,1.986,1.248,P=0.148,0.159,0.264及χ²=0.595,0.873,0.768,P=0.441,0.350,0.381). The significant differences of DMFS were not observed among N₀ and N₁, N₁ and N₂, N₂ and N₃ in 1992 staging system(χ²=3.712,3.113,2.014,P=0.054,0.078,0.156). There existed significant differences of DMFS among N₁ and N₂, N₂ and N₃ in 2008 staging system(χ²=10.488,5.059,P=0.001,0.024), N₁ and N₂ in UICC 2010staging system(χ²=7.731,P=0.0054).Conclusions The agreement of T, N and clinical stage between Chinese 2008 and UICC 2010 staging system was better than one of them compared to'92 staging system. They also indicate the radiotherapeutic prognosis in patients with nasopharyngeal carcinoma. The predictive value of radiotherapeutic prognosis of Chinese 2008 and UICC 2010 staging system were close, and were better than that of 1992 staging system in NPC.