THERAPY FOR ORAL SQUAMOUS-CELL CARCINOMA BY TEGAFUR AND STREPTOCOCCALAGENT OK-432 IN COMBINATION WITH RADIOTHERAPY - ASSOCIATION OF THE THERAPEUTIC EFFECT WITH DIFFERENTIATION AND APOPTOSIS IN THE CANCER-CELLS

Twenty patients with oral squamous cell carcinoma having mainly stage II or III lesions without distant metastasis, were treated with tegafu r and streptococcal agent, OK-432, in combination with radiotherapy. A s a consequence, 16 cases among the treated 20 cases showed complete r emission by this therapy alone, Especially, we have found that the squ amous cell carcinoma arising in non-keratinizing oral epithelium rathe r than in keratinizing oral epithelium has better response to this the rapy, Among the 16 cases with complete remission (CR) by the current t herapy, 10 cases were histopathologically diagnosed as well-differenti ated squamous cell carcinoma and six cases as moderately differentiate d squamous cell carcinoma. When we examined immunohistochemically the expression of various antigens such as proliferating cell nuclear anti gen (PCNA), p53 and Le(Y) or the presence of DNA fragmentation by nick -end labelling in the biopsy materials taken at the first visit to our clinic from 20 patients treated with the current therapy, the CR grou p showed a significantly increased Le(Y) expression level (p < 0.05) a nd DNA fragmentation rate (p < 0.05) as compared with the partial resp onse (PR, n = 3) + no change (NC, n = 1) group, On the other hand, the CR group with respect to PCNA expression level was significantly decr eased as compared with the PR + NC group (p < 0.05), From these findin gs, it can be considered that the therapy for oral squamous cell carci noma by UFT and OK-432 in combination with radiotherapy is very effect ive, which may be associated with differentiation or apoptosis in oral squamous carcinoma cells. In addition, we present the clinical findin gs and results of immunohistochemical staining for the biopsy material s obtained from four CR cases treated with the current therapeutic met hod.