Preoperative concurrent chemoradiotherapy plus radical surgery for advanced squamous cell carcinoma of the oral cavity: an analysis of long-term results.

Locoregionally advanced squamous cell carcinomas of the head and neck continue to be a major clinical problem. We demonstrated in 1996 that preoperative concurrent cisplatin- or carboplatin-based chemotherapy and radiotherapy plus radical surgery in advanced oral cancer had minimal toxicity, had high clinical tumor response rates, was well tolerated and produced impressive complete response rates and a high 5-year survival rate. The purpose of the present study was the long-term follow-up of this treatment regimen for advanced oral carcinoma. Forty-eight patients with squamous cell carcinoma of the oral cavity (including soft palate) were treated preoperatively with cisplatin- or carboplatin-based chemotherapy in combination with simultaneous irradiation to a target volume of 40 Gy, and 2-6 weeks later underwent curative surgery. All patients with advanced Stage II (n=7), Stage III (n=22) and Stage IV (n=19) were treated and followed for an average of 7.2 years (range: 61-144 months). The overall actuarial survival of all patients was 81.3% at 5 years and also at 10 years. Progression-free survival at both 5 and 10 years was 84.8% for all patients, and 85.7% for Stage II, 90.0% for Stage III, and 78.9% for Stage IV patients. Progression-free survival rates according to the histopathologic regression grade of primary tumor following preoperative chemoradiotherapy at 10 years were 40. 0% for Grade IIa, 88.9% for Grade IIb, 100% for Grade III, and 87.5% for Grade IV. Patients who achieved good responses histopathologically (Grades IIb, III, IV) had superior survival rates in comparison to patients with extensive residual tumor (Grade IIa) in surgically resected specimens (p=0.0012). A better histologic regression grade was also associated with a higher survival rate even in the long-term analysis. This treatment regimen for advanced oral cancer produced high clinical and pathologic complete response and survival rates with an acceptable acute toxicity profile and lack of late therapeutic complications. The long-term follow-up showed gratifying results even for advanced oral cancers without a substantial increase in distant metastasis and second primary malignancy.