Does Adjuvant Radiation Therapy Improve Outcomes In pT1-3N0 Oral Cavity Cancer With Tumor-Free Margins and Perineural Invasion?
Received 21 June 2007; received in revised form 30 August 2007; accepted 9 October 2007.
Purpose
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 and Materials
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 (≤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).
Conclusion
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.
∗Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
†Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
‡Department of Medical Oncology, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
§Department of Diagnostic Radiology, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
¶Department of Pathology, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
‖Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
∗∗Department of Medical Biotechnology, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
††Department of Biostatistics Consulting Center/Department of Public Health, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
‡‡Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
§§Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Chang Gung University, Taoyuan, Taiwan
Reprint requests to: Tzu-Chen Yen, MD, Ph.D., Department of Nuclear Medicine, Chang Gung Memorial Hospital at Taipei, 199, Tung Hwa North Road, Taipei 105, Taiwan, R.O.C. Tel: (+886) 3328-1200, ext. 2673; Fax: (+886) 3211-0052
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