Sister chromatid exchange frequencies in carcinoma of the human oral cavity: effect of treatment.

Abstract

Spontaneous and mitomycin-C-induced sister chromatid exchange frequencies were studied in the lymphocytes of 25 oral cancer patients. For these patients, the mean spontaneous SCE value was 8.31 (+/- SD), which was significantly higher than the value of 6.60 (+/- SD) obtained for the controls (p < 0.001). But there was no significant difference between the Mitomycin C induced mean SCE values of oral cancer patients and controls. Seven of these 25 oral cancer patients were selected for second sampling after surgical removal of the tumor. Six of these seven patients showed a decrease in mean SCE/cell value following surgery, which was almost equal to the SCE values obtained for the controls. This indicates that the increased spontaneous SCE rates in oral cancer patients might be due to the metabolic stress imposed by the tumor on the host body or by some clastogenic product of the malignant cells. Surgical removal of the tumour might have resulted in normalization of the lymphocytic SCE rates in postoperatively studied patients.