The seventh edition of the UICC/AJCC staging system for nasopharyngeal carcinoma is prognostically useful for patients treated with intensity-modulated radiotherapy from an endemic area in China

Abstract

Purpose: To evaluate the 7th edition of the International Union against Cancer/American Joint Committee on Cancer (UICC/AJCC) staging system for nasopharyngeal carcinoma (NPC) in patients treated with intensity-modulated radiotherapy.

Methods and materials: We performed a retrospective data review from 512 patients with biopsy-proven, nonmetastatic NPC in our cancer center (South China) between January 2003 and December 2006.

Results: The local relapse-free survival rates (LRFS) and disease failure-free survival rates (DFS) in the 6th edition system T1 and T2a stages were not significantly different (P=0.629 and P=0.820), while the LRFS and DFS of T1 and T2 using the 7th edition system were significantly different (P=0.019 and P=0.009). The LRFS and DFS between T2 and T3 in the 7th edition systems were lack of significance (P=0.874 and P=0.589). The total difference in distant metastasis-free survival rate and DFS between N0 and N3 was slightly larger using the 7th edition system than the 6th edition. The nodal dimension of a cervical lymph node was not a significant prognostic factor.

Conclusions: We observed a better segregation of survival curves by using the 7th edition system. It seems reasonable to downstage T3 as T2 and reject nodal greatest dimension from the N-staging system in the future revised edition.