Estimation of Invasive Front Grading and Correlation with Effect of Preoperative Chemotherapy in Oral Squamous Cell Carcinoma

Objective: This study analysed the clinicopathological predictive factors associated with the response to cisplatin- or carboplatin-based preoperative chemotherapy in patients with oral squamous cell carcinoma. Patients and Methods: Between January 1993 and December 2000, fifty two patients with resectable oral squamous cell carcinoma were treated preoperatively with cisplatin or carboplatin, and 5-fluorouracil or peplomycin. Two to 6 weeks later they underwent curative surgery. Clinicopathological factors, especially histological grading in the deep invasive front were analysed to determine factors predicting the response to preoperative chemotherapy and their influence on the prognosis. Results: The pattern of residual viable tumour cell (r-Pattern) was correlated with invasive front grading. The mean invasive front grading score was significantly higher in the poor response (r-Pattern III) group than in the group with a good response to preoperative chemotherapy. Multivariate analysis demonstrated that only invasive front grading (≥10 points) had a predictive value for r-Pattern to preoperative chemotherapy and disease-free survival (odds ratio = 32.10, p = 0.002 and hazards ratio = 6.62, p = 0.0142). Conclusions: These findings suggest that the invasive front grading is one of the most important factors for predicting both the response to preoperative chemotherapy and the prognosis of patients with oral squamous cell carcinoma.