Response to induction chemotherapy as predictive marker of tumor response to radiotherapy and survival in oral cavity cancer

Background: Trials have shown some statistically nonsignificant survival advantage of taxane, platin and 5-FU (TPF) induction chemotherapy before definitive chemoradiation. We tried to find the role of induction chemotherapy in the prediction of tumor response to radiotherapy and survival in the treatment of oral cavity cancers. Patients and Methods: Patients of stage III and IV (M0) unresectable oral cavity squamous cell carcinoma were assigned to receive two cycles of TPF. On the basis of response to chemotherapy, two groups were made. Those who had partial or more than partial response and another group who had stable disease or disease progression during chemotherapy. Concurrent chemoradiotherapy was given to all patients after induction chemotherapy. Results: A total of 128 patients who received TPF, 29 (22.6%) had complete response, 57 (44.5%) had partial response, 38 (29.7%) had stable disease and 4 (3.1%) had progressive disease. Definitive chemoradiotherapy lead to complete response in 48 (55.8%) patients who had partial or more than partial response (total 86) to chemotherapy and 10 (23.8%) patients among those who had stable disease or disease progression during chemotherapy (total 42). This difference in response is statistically significant (P = 0.001). Three years survival was significantly better after treatment in patients who responded more than partial (hazard ratio 0.463, 95% confidence interval 0.2789-0.7689), with an estimated 3-year survival of 35% in patients in group 1 and 14% in group 2. Conclusion: Response to induction chemotherapy can be a predictive marker for response to subsequent chemoradiotherapy and survival, with acceptable toxicities.