Abstract Objective To evaluate the 7th edition of the International Union against Cancer/American Joint Committee on Cancer (UICC/AJCC) staging system for nasopharyngeal carcinoma (NPC), and to provide a basis for its further revision. Methods Three hundred and twenty-three patients who were pathologically diagnosed with NPC (without distant metastasis) and received radical intensity-modulated radiotherapy (IMRT) in our hospital from 2005 to 2011 were enrolled as subjects. All patients were staged according to the 7th edition of the UICC/AJCC staging system. The overall survival (OS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) rates were calculated using the Kaplan-Meier method, and pairwise comparisons were made by the log-rank test. Multivariate prognostic analyses were performed using the Cox regression model. Results The 5-year sample size was 45. There were no significant differences in 5-year LRFS between stages T1 and T2, as well as between stages T2 and T3(P=0.055;P=0.746). The current stages T2, T3, and T4 with only medial pterygoid muscle were combined into stage T2, and the rest of stage T4 were down-staged to stage T3. In the new T staging system, the LRFS curves of stages T1, T2, and T3 were substantially separated. There were no significant differences in 5-year DMFS between stage N2 and N3a, between stage N2 and N3b, and between stages N3a and N3b (P=0.272;P=0.063;P=0.810). Multivariate analyses demonstrated that cervical lymph node metastasis was the only independent prognostic factor for DMFS (P=0.037). The current stage N3a with cervical lymph node metastasis on one side was down-staged to stage N1, and the current stage N3a with cervical lymph node metastasis on both sides to stage N2. In the new N staging system, the DMFS curves of stages N0, N1, N2, and N3 were substantially separated. There were no significant differences in 5-year OS between stages I and II, as well as between stages III and IVa (P=0.434;P=0.951). The current stages T1N0-1, T2N0-1, T1-3N2/T3N0-1, and T1-3N3 were classified into stage Ia, Ib, II, and III, respectively. In the new staging system, the 5-year OS curves of stages Ia, Ib, II, and III were substantially separated. Conclusions There are several deficiencies in the 7th edition of the UICC/AJCC staging system. The proposed new staging system can achieve a better prognosis, though further validations with a larger sample size are needed. DOI:10.3760/cma.j.issn.1004-4221.2015.03.014 作者单位:330029 南昌,江西省肿瘤医院放疗科 通信作者:李金高,Email:lijingao@hotmail.com
Corresponding Authors:
Li Jingao,Email:lijingao@hotmail.com
Cite this article:
Zeng Lei,Gong Xiaochang,Ao Fan et al. Evaluation of staging system for nasopharyngeal carcinoma based on intensity-modulated radiotherapy[J]. Chinese Journal of Radiation Oncology, 2015, 24(3): 285-288.
Zeng Lei,Gong Xiaochang,Ao Fan et al. Evaluation of staging system for nasopharyngeal carcinoma based on intensity-modulated radiotherapy[J]. Chinese Journal of Radiation Oncology, 2015, 24(3): 285-288.
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