title: Prognostic significance of perineural invasion in oral and oropharyngeal carcinoma.
abstract: OBJECTIVE
  To evaluate the occurrence and prognostic significance of perineural invasion (PNI) in squamous cell carcinomas (SCC) of the oral cavity and oropharynx.
  
  
  METHODS
  A retrospective study of 101 patients with previously untreated SCC of the oral cavity and oropharynx was undertaken to evaluate the occurrence and prognostic significance of PNI in relation to local recurrence, regional recurrence, distant metastasis and survival. The logistic regression test was used for univariate and multivariate analyses. Actuarial survival curves were determined using the Kaplan-Meier method.
  
  
  RESULTS
  PNI was present in 26 (25.7%) of 101 patients and was significantly associated with tumor differentiation, lymph node metastasis, and depth of invasion. Univariate analyses showed PNI was associated with local recurrence (P=.005), regional recurrence (P=.007), and distant metastasis (P=.013). In multivariate analysis, PNI was significantly associated with regional recurrence (P=.033) and distant metastasis (P=.021), but not with local recurrence (P=.109). The 5-year disease-specific survival for patients with and without PNI was 56.6% and 94.6%, respectively (P<.0001).
  
  
  CONCLUSIONS
  PNI is an important predictor for outcome of patients with SCC of the oral cavity and oropharynx.
authors.affiliation: First Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Niigata University, Niigata City, Japan.
authors.forename: Bibi
authors.initials: B
authors.lastname: Rahima
authors.forename: Susumu
authors.initials: S
authors.lastname: Shingaki
authors.forename: Masaki
authors.initials: M
authors.lastname: Nagata
authors.forename: Chikara
authors.initials: C
authors.lastname: Saito
mesh_terms: D000206:Actuarial Analysis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000145:classification / Q000473:pathology* / Q000556:secondary; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology*; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000473:pathology*; D010525:Peripheral Nerves / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis