title: Should All Nasopharyngeal Carcinoma with Paranasal Sinus Invasion Be Staged as T3 in the Intensity-Modulated Radiotherapy Era? A Study of 1811 Cases.
abstract: BACKGROUND
  Currently, there is no uniform consensus regarding the appropriate staging for invasion of the paranasal sinuses in nasopharyngeal carcinoma (NPC). In the current AJCC staging system for NPC, paranasal sinus invasion is defined within the T3 classification. However, according to the Chinese 2008 staging system, which is also widely used in the regions where NPC is endemic in China, paranasal sinus invasion is classified as T4 disease.
  
  
  METHODS
  Patients (n = 1811) with non-metastatic, histologically-proven NPC treated with intensity-modulated radiotherapy (IMRT) were retrospectively analyzed.
  
  
  RESULTS
  Paranasal sinus invasion was identified in 289/1811 patients (16.0%). Multivariate analysis revealed ethmoid sinus invasion (HR, 2.889; 95% CI, 1.362-6.131; P = 0.006) and maxillary sinus invasion (HR, 3.110; 95% CI, 1.439-6.721; P = 0.004) were independent prognostic factors for local relapse-free survival (LRFS). T3 patients with ethmoid sinus or maxillary sinus invasion had similar 3-year LRFS (83.6% vs. 92.2%, P = 0.132) as T4 patients, and had poorer LRFS (83.6% vs. 98.3%, P = 0.006) than T3 patients with sphenoid sinus invasion alone. Also, T3 patients with sphenoid sinus invasion alone had similar 3-year LRFS (98.3 vs. 96.4%, P = 0.391) as T3 patients without paranasal sinus invasion, and a trend toward higher LRFS (98.3% vs. 92.2%, P = 0.065) than T4 patients.
  
  
  CONCLUSIONS
  In patients underwent IMRT, tumors with ethmoid sinus or maxillary sinus invasion had a higher risk of local failure than those with sphenoid sinus invasion alone. Sphenoid sinus invasion alone should be classified as T3 disease and ethmoid sinus or maxillary sinus involvement as T4 disease in the current AJCC staging system for NPC.
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Peng
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Guo
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Li
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Ling-Long
authors.initials: LL
authors.lastname: Tang
authors.affiliation: 2. Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Li-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.affiliation: 2. Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: 3. Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Canton, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton, Guangdong Province, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
keywords: nasopharyngeal neoplasms; neoplasm staging.; paranasal sinuses; prognosis; radiotherapy, intensity-modulated