title: Nasopharyngeal carcinoma with skull base invasion: a necessity of staging subdivision.
abstract: OBJECTIVE
  To investigate prognostic values of nasopharyngeal carcinoma (NPC) with skull base invasion for optimal management, according to its extent of involvement.
  
  
  METHODS
  From January 1985 through December 2000, 119 patients with histologically proven NPC were analyzed retrospectively with review of their computed tomography/magnetic resonance imaging and medical records. All patients underwent sequential chemoradiotherapy except 2 cases, which were treated concurrently. The mean duration of follow-up was 61 months (range 8-179). Potential prognostic factors were evaluated by univariate and multivariate analyses by the Kaplan-Meier method and the Cox model, with a particular emphasis on the extent of skull base invasion.
  
  
  RESULTS
  Skull base invasion was found in 46 (38.6%) of 119 patients. Cranial nerve palsy and intracranial extension was discovered in 34 (28.6%) and 23 (19.3%) of these patients, respectively. The sole erosion of the skull base was not found to be a poor prognostic factor. Patients with involvement of both anterior (I-VIII) and posterior (IX-XII) cranial nerves had a worse prognosis than those with involvement of either anterior or posterior cranial nerves (P = 0.0219). The presence of intracranial extension was the worst prognostic factor in NPC with skull base invasion (P = 0.0269). The advanced neck stage and histology did not affect the prognosis of NPC in the presence of skull base invasion.
  
  
  CONCLUSIONS
  Our results show that NPC with skull base invasion should be divided into the groups with, simple skull base erosion, minimal involvement of either anterior or posterior cranial nerves, multiple involvements of both cranial nerves, and intracranial extension.
authors.affiliation: Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejon, Korea.
authors.forename: Jong-Lyel
authors.initials: JL
authors.lastname: Roh
authors.forename: Myung-Whun
authors.initials: MW
authors.lastname: Sung
authors.forename: Kwang Hyun
authors.initials: KH
authors.lastname: Kim
authors.forename: Byung Yoon
authors.initials: BY
authors.lastname: Choi
authors.forename: Seung Ha
authors.initials: SH
authors.lastname: Oh
authors.forename: Chae Seo
authors.initials: CS
authors.lastname: Rhee
authors.forename: Jung Whun
authors.initials: JW
authors.lastname: Ha
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D019292:Skull Base Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed