title: A new staging system for nasopharyngeal carcinoma based on intensity-modulated radiation therapy: results of a prospective multicentric clinical study.
abstract: OBJECTIVE
  To establish a new clinical staging standard for nasopharyngeal carcinoma (NPC), based on intensity-modulated radiotherapy (IMRT), through a prospective multicenter clinical trial.
  
  
  METHODS
  492 NPC patients were selected from six hospitals in the Guangxi Zhuang Autonomous Region, China from January 2006 to December 2009. Kaplan-Meier method was adopted to calculate survival rates. Log-rank test was used to compare survival differences.
  
  
  RESULTS
  According to the seventh edition of the UICC/AJCC staging system, the differences between T1, T2 and T3 are not statistically significant, suggesting that T1, T2 and T3 could be combined as new T1. There were significant differences between all N stages except those of N3a and N3b, suggesting that N3a and N3b could be combined as new N3. Additionally, the overall survival (OS) curves of stages I, II, III and IVa were not significantly different. Therefore, we propose a new clinical NPC staging standard based on magnetic resonance imaging (MRI) and IMRT as T stage (including T1 and T2) , N stage (including N0, N1, N2 and N3) and clinical staging includes I (T1N0M0), II (T1N1-2M0, T2N0M0), III (T2N1-2M0), IVa (TxN3M0) and IVb (TxNxM1). Recommended staging system performs better in risk difference and distribution balance . Furthermore, the differences in the 5-year curves of local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and OS were all statistically more significant than the seventh edition of the UICC/AJCC staging system.
  
  
  CONCLUSIONS
  Proposed staging system is more adaptable to IMRT and predicts the prognosis of NPC patients more accurately.
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, P.R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Kang
authors.affiliation: School of Public Health, Guangxi Medical University, Nanning, Guangxi, P.R. China.
authors.forename: Jianxiong
authors.initials: J
authors.lastname: Long
authors.affiliation: Department of Radiation Oncology, Liuzhou Worker Hospital, Liuzhou, Guangxi, P.R. China.
authors.forename: Guisheng
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, First People's Hospital of Yulin City, Yulin, Guangxi, P.R. China.
authors.forename: Haolin
authors.initials: H
authors.lastname: Yan
authors.affiliation: Department of Radiation Oncology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, P.R. China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Feng
authors.affiliation: Department of Radiation Oncology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, P.R. China.
authors.forename: Meilian
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Wuzhou Red Cross Hospital, Wuzhou, Guangxi, P.R. China.
authors.forename: Jinxian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, P.R. China.
authors.forename: Rensheng
authors.initials: R
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology* / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D009367:Neoplasm Staging / Q000592:standards*; D011446:Prospective Studies; D050397:Radiotherapy, Intensity-Modulated; D015996:Survival Rate; D055815:Young Adult
keywords: intensity modulated radiation therapy; nasopharyngeal carcinoma; prognosis; staging systerm