Nasopharyngeal carcinoma treated with intensity-modulated radiotherapy: clinical outcomes and patterns of failure among subsets of 8th AJCC stage IVa
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The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for nasopharyngeal carcinoma (NPC) merged T4N0–2 and T1–4N3 to create stage IVa. In the present study, we aimed to assess the difference in clinical outcomes and patterns of failure between 8th AJCC T4N0–2 and T1–4N3 NPC patients treated with intensity-modulated radiotherapy (IMRT).
We included 3107 patients with stage IVa NPC disease (1871 with T4N0–2 and 1236 with T1–4N3) according to the 8th AJCC staging system. Overall survival (OS) was the primary endpoint. The clinical outcomes between T4N0–2 and T1–4N3 patients were compared.
T1–4N3 patients had significantly worse 3-year OS (84.1% vs. 89.2%; p < 0.001) and distant metastasis–free survival (DMFS; 78.3% vs. 85.9%; p < 0.001), but better local relapse–free survival (LRFS; 94.9% vs. 92.2%; p = 0.003), as compared with T4N0–2 patients. Multivariate analysis showed that T1–4N3 was still an independent adverse prognostic factor for both DMFS (hazard ratio [HR] = 1.517, 95% confidence interval [CI] = 1.274–1.806, p < 0.001) and OS (HR = 1.315, 95% CI = 1.100–1.572, p = 0.003), whereas T4N0–2 was an independent adverse prognostic factor for LRFS (HR = 1.581, 95% CI = 1.158–2.158, p = 0.004).
In terms of the OS, T4N0–2 patients had better prognosis compared with T1–4N3 patients, and the patterns of failure differed between T4N0–2 and T1–4N3 patients. We believe that future modifications of the AJCC/UICC staging system should separate T4N0–2 from T1–4N3.
• In nasopharyngeal carcinoma, T4N0–2 patients tended to develop local relapse, whereas T1–4N3 patients were more likely to develop distant metastasis.
• In terms of overall survival, T4N0–2 patients had better prognosis than T1–4N3 patients.
• T4N0–2 should be separated from T1–4N3 in the UICC/AJCC staging system.
KeywordsPrognosis Treatment failure Stage Nasopharyngeal carcinoma Intensity-modulated radiotherapy
American Joint Committee on Cancer/Union for International Cancer Control
Distant metastasis–free survival
Gross tumor volume
Local relapse–free survival
Magnetic resonance imaging
Positron emission tomography CT
Regional relapse–free survival
Single photon emission computed tomography
This work was supported by the Natural Science Foundation of China (grant number 81572962), the Natural Science Foundation of Guangdong Province (grant number 2017A030312003), the Health & Medical Collaborative Innovation Project of Guangzhou City, China (grant number 201803040003), the Innovation Team Development Plan of the Ministry of Education (grant number IRT_17R110), and the Overseas Expertise Introduction Project for Discipline Innovation (111 Project), (grant number B14035).
Compliance with ethical standards
The scientific guarantor of this publication is Ling-Long Tang from Sun Yat-sen University Cancer Center (Guangzhou, China).
Conflict of interest
The authors declare that they have no conflict of interest.
Statistics and biometry
One of the authors, Ai-Hua Lin, who is from the Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University (Guangzhou, China), has significant statistical expertise.
Written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
• Diagnostic or prognostic study
• Performed at one institution
- 2.Amin MB, American Joint Committee on Cancer (2016) AJCC cancer staging manual, 8th edn. Springer, New YorkGoogle Scholar
- 17.Chen YP, Wang ZX, Chen L et al (2015) A Bayesian network meta-analysis comparing concurrent chemoradiotherapy followed by adjuvant chemotherapy, concurrent chemoradiotherapy alone and radiotherapy alone in patients with locoregionally advanced nasopharyngeal carcinoma. Ann Oncol 26:205–211CrossRefGoogle Scholar