Preoperative radiochemotherapy has been carried out for many cases of oral cancers to improve locoregional control. The purpose of this study was to evaluate whether preoperative radiochemotherapy for oral squamous cell carcinomas is beneficial for the patients.
A retrospective analysis of 182 patients who had successfully undergone operations at our hospital from April 1982 to March 2001 was performed. Subjects consisted of a preoperative radiochemotherapy group (n=88) and a surgery-only group (n=94). We obtained the following results and conclusions:
1. Preoperative radiochemotherapy for advanced oral squamous cell carcinomas (Stage III, IV) did not contribute to improvement of the survival rate, although it was effective for locoregional control. These results indicated that preoperative radiochemotherapy could decrease the reoperations of recurrences and regional lymph node metastases. Therefore, organ preservations were done in some cases by preoperative radiochemotherapy.
2. The preoperative radiochemotherapy effective group showed a better survival rate than the noneffective group, and the response rate of preoperative radiochemotherapy became an independent predictive factor for the prognosis. The 5-year cause-specific survival rate in Stage III, IV was 88.8% for the effective group and 55.8% for the noneffective group.
3. The cause of death in the noneffective group was mainly local recurrence mostly arising from a deep region of the tumor surgical margin, and 75.0% of the dead cases were cases with mode of invasion 4C or 4D. Therefore, we should consider setting a larger safety margin especially in the deep region of a tumor that is highly invasive and for which radiochemotherapy is not effective.
