Does adjuvant radiation therapy improve outcomes in pT1-3N0 oral cavity cancer with tumor-free margins and perineural invasion?
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.
Liao
Chun-Ta
CT
Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
Chang
Joseph Tung-Chieh
JT
Wang
Hung-Ming
HM
Ng
Shu-Hang
SH
Hsueh
Chuen
C
Lee
Li-Yu
LY
Lin
Chih-Hung
CH
Chen
I-How
IH
Huang
Shiang-Fu
SF
Cheng
Ann-Joy
AJ
See
Lai-Chu
LC
Yen
Tzu-Chen
TC
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