title: Does adjuvant radiation therapy improve outcomes in pT1-3N0 oral cavity cancer with tumor-free margins and perineural invasion?
abstract: OBJECTIVE
  The criteria for administration of adjuvant radiation therapy (RT) in oral cavity squamous cell carcinoma (OSCC) remain controversial, and it is unclear whether patients with pT1-3N0 disease benefit from adjuvant radiation in the presence of free margins and perineural invasion. The goal of this report was to determine whether this group would benefit from adjuvant radiation therapy in terms of 5-year local control rate and overall survival rate.
  
  
  METHODS
  We retrospectively reviewed our case records from January 1996 to May 2005. In all, 460 pT1-3N0 OSCC patients had tumor-free margins, of whom 68 had perineural invasion. Postoperative adjuvant RT was performed in patients with pT4 tumors, positive lymph nodes, or close margins (< or =4 mm). In addition, selected OSCC patients with large pT3 tumors or perineural invasion received postoperative adjuvant RT. Local control and overall survival rates were plotted by Kaplan-Meier analysis.
  
  
  RESULTS
  There were no significant differences in 5-year local control (p = 0.1936) and overall survival (p = 0.5580) rates between patients with perineural invasion compared with those without. Among patients with perineural invasion, the addition of adjuvant radiotherapy did not significantly alter the 5-year local control rate (p = 0.3170) or the overall survival rate (p = 0.0935).
  
  
  CONCLUSIONS
  Altogether, these data seem to indicate that radical surgical resection alone should be considered a sufficient treatment for OSCC patients with pT1-3N0 disease, even in the presence of perineural invasion.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.forename: Joseph Tung-Chieh
authors.initials: JT
authors.lastname: Chang
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Wang
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
authors.forename: Chuen
authors.initials: C
authors.lastname: Hsueh
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Lee
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Lin
authors.forename: I-How
authors.initials: IH
authors.lastname: Chen
authors.forename: Shiang-Fu
authors.initials: SF
authors.lastname: Huang
authors.forename: Ann-Joy
authors.initials: AJ
authors.lastname: Cheng
authors.forename: Lai-Chu
authors.initials: LC
authors.lastname: See
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D015996:Survival Rate