Elsevier

European Journal of Cancer

Volume 51, Issue 13, September 2015, Pages 1771-1779
European Journal of Cancer

New surgical staging system for patients with recurrent nasopharyngeal carcinoma based on the AJCC/UICC rTNM classification system

https://doi.org/10.1016/j.ejca.2015.05.014Get rights and content

Abstract

Background

Recurrent tumour, node and metastasis (rTNM) stage system does not have an outstanding prognostic value for survival outcome of patients with recurrent nasopharyngeal carcinoma (rNPC) and it cannot aid the clinicians to choose the most suitable treatment for these patients.

Methods

In total, 894 rNPC patients were consecutively enroled. All recurrent (r) tumour (T) stages (rT) and node (N) stages (rN) were stratified as resectable and unresectable based on the imaging data of the head and neck. These stages were re-subdivided into surgical T stages (sT) and surgical N stages (sN) with similar clinical characteristics and death risks and were re-integrated into a new ‘surgical’ stage using a Cox proportional hazards model.

Results

The 5-year overall survival (OS) was 72.0%, 55.1%, 21.1% and 10.1% in ‘surgical’ stages I, II, III and IV, respectively (P < 0.001). The ‘surgical’ stage was a significant independent prognostic factor for OS (hazard ratio [HR] 1.78, P < 0.001) and exhibited enhanced prognostic value compared with the rTNM staging system (area under receiver operating characteristics 0.68 versus 0.63, P < 0.001). Endoscopic nasopharyngectomy and intensity-modulated radiation therapy were significant independent positive prognostic factors for the OS of patients with primary lesions in ‘surgical’ stage I/II and ‘surgical’ stage III, respectively (P < 0.05). A combination of aggressive treatments for loco-regional lesions exhibited a beneficial trend for OS of patients with ‘surgical’ stage IV (P > 0.05).

Conclusions

Compared with the rTNM stage system, the ‘surgical’ staging system exhibited enhanced prognostic value for rNPC patient survival and could aid clinicians in choosing the most suitable treatment for rNPC patients.

Introduction

The American Joint Committee on Cancer (AJCC/UICC) tumour, node and metastasis (TNM) staging [1] is the most commonly used cancer staging system for newly diagnosed nasopharyngeal carcinoma (NPC). According to the 2011 National Comprehensive Cancer Network (NCCN) guidelines for head and neck cancer [2], concurrent chemoradiotherapy with or without induction chemotherapy is the standard treatment for T1 N1-3 M0 or T2-4 N any M0 patients. In addition, palliative platinum-based combination chemotherapy is recommended as the primary treatment for patients with distant metastases (any T, any N and M1). The five-year overall survival (OS) rates for non-metastatic NPC patients treated with intensity-modulated radiation therapy (IMRT) were 100%, 94.3%, 83.6% and 70.4% for stages I, II, III and IV, respectively [3].

However, 8.4–10.9% of patients developed recurrent disease at the primary or/and regional site after definitive radiotherapy [4], [5]. The current recurrent AJCC/UICC TNM stage system (rTNM) uses the ‘r’ prefix to denote the TNM stage for relapse patients. Therefore, rTNM staging ignores the striking differences between recurrent and primary patient populations, and the system may exhibit reduced critical accuracy when applied to recurrent diseases. For example, according to the sixth AJCC TNM staging manual [1], the survival of stage III recurrent nasopharyngeal carcinoma (rNPC) patients is similar to those re-staged as stage IV even when administered the same IMRT treatment method, thus indicating minimal difference between rT3 and rT4 [6], [7]. Furthermore, rN classification exhibited no prognostic significance regarding OS [6]. As a well-established technique, radiotherapy plays an important role as a salvage treatment for rNPC patients and is applied in all rT1–rT4 classifications [6], [7]. However, reduced radiation tolerance in the proximity of critical structures limits the application of salvage re-irradiation to those types of recurrences [8]. Endoscopic nasopharyngectomy (ENPG) is the most reasonable choice for rNPC. However, only some patients with limited lesions are suitable for salvage surgery [9]. Chemotherapy is also applicable for the management of rNPC but only serves as a palliative treatment [10]. In general, many modalities, including salvage surgery, re-irradiation and chemotherapy, are effective treatments for rNPC patients; however, none of these treatments were indicated according to the rTNM classification system. Thus, clinicians find it difficult to choose the most suitable treatment for rNPC patients in each stage. This fact prompted us to develop a specialised staging system for rNPC to correctly predict the survival of rNPC patients, aid the clinicians in planning treatments and facilitate clinical data sharing among different countries and hospitals.

Section snippets

Patient selection

Between 1st January 2000 and 31st December 2009, a total of 1102 consecutive patients with histologically or radiologically confirmed loco-regional recurrent diseases (first failures) who received radical radiotherapy initially before recurrence at the Sun Yat-sen University Cancer Center (SYSUCC) were enroled in this study. All of the patients with rNPC were initially staged according to the 2002 AJCC/UICC classification system [1]. Our exclusion criteria included (1) patients with missing

Clinicopathological characteristics

The clinicopathological characteristics of all 894 patients are presented in Appendix Table 1. On the final follow-up date (1st January 2013), the median follow-up was 50.35 months (range, 4.10–148.97 months) and a total of 494 patients died. The 5-year OS was 40.8%.

Recurrent T, N and M stages were converted into relative ‘surgical’ T, N and M stages

Totally, 385 patients underwent contrast-enhanced CT and the remaining 509 patients underwent MR imaging. Based on these imaging data, rNPC patients with rT2b, rT3, rN1, rN2 and rN3 were stratified into resectable or unresectable.

Discussion

An excellent staging system should both have a good prognostic value for survival outcome and be a good indicator of treatment choice. However, accumulating data have demonstrated that the popular rTNM staging system for rNPC does not meet these standards. Various specially designed recurrent staging systems were reported to demonstrate enhanced prognostic value for patients with recurrent head and neck cancers, such as recurrent laryngeal, oral cavity and oropharyngeal carcinoma [12], [13].

Conflict of interest statement

None declared.

Acknowledgements

This work was supported in part by the Program for New Century Excellent Talents in University of China (NCET-12-0562), Sun Yat-sen University – China Clinical Research 5010 Program (201310), Guangdong Provincial Natural Science Foundation of China (S2013020012726) and National High Technology Research and Development Program of China (863 Program, No. 2012AA02A501).

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