Preliminary results of a prospective multicenter study on clinical staging system for nasopharyngeal carcinoma

Abstract

Objective To compare patient distributions and prognostic value between the 2008 and the 7 th edition of the International Union against Cancer/American Joint Committee on Cancer (UICC/ AJCC) staging systems for nasopharyngeal carcinoma (NPC), and to investigate their rationality. Methods The clinical data of 1508 patients with untreated NPC (without distant metastasis) who were admitted to 9 national cancer centers from 2009 to 2010 were analyzed. All patients were staged according to the above two staging systems in order to evaluate the agreement in patient distributions between the two staging systems and analyze the 3-year local recurrence-free survival (LRFS), distant metastasis-free survival ( DMFS), and overall survival (OS) rates. The LRFS, DMFS, and OS rates were calculated using the Kaplan-Meier method, and pairwise comparisons were performed using the log-rank test. Results There were no significant differences in patient distributions with T, N, and clinical staging classifications between the two systems ( Kappa = 0. 80, 0. 60, and 0. 60). The OS curves with clinical staging classification and the LRFS curves with T staging classification were also similar. However, in both staging systems, the OS curves with stage I and stage Ⅱ were similar, and the LRFS curves with stages T1 -T3 were close or even overlapped. There were no significant differences in the DMFS curves between stages N0 and N1 in the 2008 staging system, as well as between stages N1 and N2 in the UICC/AJCC staging system. Conclusions In the two staging system, the patient distributions and prognoses of clinical and T staging classifications are similar, whereas the prognoses of N staging classification are different. The prognoses of clinical, T, and N staging classifications need to be improved for both staging systems. Key words: Nasopharyngeal neoplasms/radiotherapy; Staging system; Prognosis