SPONTANEOUS AND MITOMYCIN-C INDUCED SISTER-CHROMATID EXCHANGE (SCE) FREQUENCIES IN PATIENTS WITH PREMALIGNANT AND MALIGNANT ORAL LESIONS

Spontaneous and mitomycin-C induced sister chromatid exchange (SCE) fr equencies were studied using lymphocytes of 25 patients with oral canc er and 20 patients with oral submucous fibrosis (OSMF). Two control po pulations consisting of 25 age and sex matched normals and 20 chronic chewers were also analyzed concurrently. The spontaneous SCE frequenci es in chronic chewers, OSMF and oral cancer patients were higher than the normal control SCE values though statistically not significant. Ho wever, the mitomycin-C induced SCE rates showed no difference between the patients and the controls. Three OSMF patients and 2 chronic chewe rs showed very high spontaneous SCE rates. On follow up, it was found that these 5 subjects transformed into oral malignant and premalignant lesions respectively within a period of 3 years. Analysis of SCE rate s seems to be a useful technique for identifying individuals with a hi gh risk for oral cancer.