Elevated sister chromatid exchange frequencies in the lymphocytes of esophageal cancer patients.

Thirty patients with esophageal cancer and 35 healthy controls were studied for spontaneous and mutagen-induced sister chromatid exchange (SCE) frequencies and cellular kinetics in peripheral blood lymphocytes. Some of the patients and controls were tobacco consumers (TC). A mean spontaneous SCE per cell value of 8.36 obtained for the patients was higher significantly (P less than 0.001) compared with a SCE per cell value of 6.74 for the controls. It was noticed that the elevation was significant even when persons in both groups were separated and compared on the basis of tobacco consumption. Among the controls, TC had higher SCE compared with non-tobacco consumers (NTC) (P less than 0.01). Mitomycin C (MMC) was used as a mutagen. No significant difference was observed in MMC-induced rates of SCE between the patients and controls. The cellular kinetics, expressed as average generation time (AGT), also were comparable in both groups. It was concluded that either metabolic stress imposed by the tumor or some clastogenic secretion of malignant cells was responsible for elevated SCE rates in the lymphocytes of the esophageal cancer patients. The disease had no effect on mutagen-induced SCE rates or cellular kinetics in lymphocytes.