title: Prognostic value of prevertebral space involvement in nasopharyngeal carcinoma based on intensity-modulated radiotherapy.
abstract: OBJECTIVE
  To investigate the prognostic significance of prevertebral space involvement (PSI) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT).
  
  
  METHODS
  A retrospective review of data from 506 biopsy-proven, nonmetastatic NPCs was performed. Patients underwent magnetic resonance imaging examinations and received IMRT as their primary treatment.
  
  
  RESULTS
  In this series, 161 NPC patients (31.8%) had PSI. Parapharyngeal space (p < 0.001), skull base (p < 0.001), and paranasal sinuses (p = 0.009) were associated with PSI after multivariate analysis. The 4-year overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS) for NPC patients with and without PSI was 69.1% and 89.2% (p < 0.0001), 83.9% and 96.4% (p < 0.0001), and 71.6% and 89.6% (p < 0.0001), respectively. Multivariate analysis identified PSI as an independent negative prognostic factor for both OS (HR = 1.478-4.380; p = 0.001) and DMFS (HR = 1.389-4.174; p = 0.002). Patients with PSI had similar survival rates in OS and DMFS (p = 0.241 and p = 0.493, respectively) to that of T4 disease, while the differences between PSI and T3 disease in both OS and DMFS were distinctly significant (p = 0.029 and p = 0.029, respectively).
  
  
  CONCLUSIONS
  For NPC patients treated with IMRT, PSI was found to be an independent prognostic factor for both OS and DMFS. It seems reasonable that PSI should be classified as a T4 disease on the basis of the current American Joint Committee on Cancer staging classification criteria.
authors.affiliation: State Key Laboratory of Oncology in Southern China, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Guan-qun
authors.initials: GQ
authors.lastname: Zhou
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Mao
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Li
authors.forename: Li-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Tian
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Lin
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002277:Carcinoma; D002574:Cervical Vertebrae / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult