A total of 44 patients with oral squamous cell carcinoma of stage III or N, treated by neoadjuvant chemotherapy followed by radical surgery were investigated, to elucidate the clinical significance of Bax expression for predicting chemotherapeutic effects. Immunohistochemistry for Bax protein was carried out on serial sections from f ormalin-f ixed, paraffinembedded tissues, which were classified into Bax positive and Bax negative. The effects of neoadjuvant chemotherapy were evaluated according to general rules for clinical and pathological studies on head and neck cancer by the Japan Society for Head and Neck Cancer, the Oboshi-Shimosato grade, and classification of variation of kinetic proliferation based on DNA contents and the mitotic index. Bax expression was associated with favorable effects of neoadjuvant chemotherapy. The five-year cumulative survival rate was 70% for the whole series, 90% for Bax-positive patients, and 52% for Bax-negative. Baxpositive patients had a statistically high survival rate compared with Bax-negative (P=0.01). From these results, it was suggested that Bax expression serves as a predictive indicator for neoadjuvant chemotherapy, and as a prognostic factor for survival.
