SISTER-CHROMATID EXCHANGE STUDIES FOR MONITORING DNA-DAMAGE IN LYMPHOCYTES OF MALIGNANT-LYMPHOMA PATIENTS UNDER CYTOSTATIC THERAPY

Sister chromatid exchange (SCE) frequencies were studied in lymphocyte s from 45 patients with malignant lymphoma. Fifteen patients were untr eated when studied. The mean SCE frequency for these patients was 8.70 +/- 0.99 per mitosis. The mean score for 35 controls was 4.37 +/- 1.1 9. SCE mean scores were significantly higher in the untreated patients than in the controls (p < 0.001). Nine patients were treated with rad iotherapy alone. The mean SCE frequency (6.80 +/- 0.87) they demonstra ted was significantly lower (p <0.01) than that found in untreated pat ients. Twelve patients received cyclophosphamide 1 month before the st udy was started. They demonstrated a mean SCE frequency (12.00 +/- 1.3 1) significantly higher (p < 0.05) than that found in patients who had received regimens that did not contain cyclophosphamide (9.72 +/- 1.3 2). From these findings we suggest that untreated patients with malign ant lymphoma have elevated SCE frequencies, which may be further incre ased by chemotherapeutic agents.