Long-term survival of patients with primary oral squamous cell carcinoma. Comparison of two treatment protocols in a prospective study

Background and Purpose: In recent years, different concepts for the treatment of oral squamous cell carcinomas (OSCC) have been developed; these include preoperative simultaneous neoadjuvant radiochemotherapy and one-stage surgery with tumor ablation and reconstruction. When considering long-term survival, there is substantial evidence that multimodality treatment based on a neoadjuvant radiochemotherapy is superior to adjuvant therapy concepts based on a surgical approach with postoperative irradiation. The aim of this study was to discuss the 5-year survival rate in a neoadjuvant and an adjuvant combination treatment in patients with primary OSCC. Patients and Methods: This nonrandomized longitudinal study prospectively evaluates the long-term tumor-free survival in 128 patients with oral cancer. Two groups consisting of 74 neoadjuvantly and 54 primarily surgically treated patients were formed. 99 patients suffered from stage III and IV disease according to the UICC criteria. Long-term survival was estimated according to the Kaplan-Meier assumption. Results: The neoadjuvant treatment increases the prospect of a long-term tumor-free survival. According to Kaplan-Meier assumption the estimation for a 5-year tumor-free survival in OSCC in category T1 is 83.1% in neoadjuvant, and 70.1% in adjuvant treatment, in T2 79.6% and 57.7%, in T3 68.2% and 33.2%, in T4 51.4% and 30.5%, respectively. Significance (p < 0.05) could be proven for T1 (p = 0.002), T2 (p = 0.028), and T4 (p < 0.0001) tumors. The effectiveness of the preoperative radiochemotherapy was demonstrated in the pathohistological result of tumor-free resection specimens in 28 patients of the neoadjuvant treatment group (37.8%). On the other hand, four patients died during the preoperative combination therapy. 64.8% of the patients in the adjuvant and 71.6% in the neoadjuvant treatment group survived the observation period. Conclusion: Neoadjuvant therapy is highly effective and results in a better 5-year survival rate than adjuvant treatment. All patients with primary OSCC should be selected for such a treatment. Future therapy concepts should combine the effectiveness of a systemic treatment with the safety of a limited surgical resection of the tumor site to preserve as much function as possible.