CHROMOSOMAL-ABERRATIONS DETECTED BY CHROMOSOME PAINTING IN LYMPHOCYTES FROM CANCER-PATIENTS GIVEN HIGH-DOSES OF THERAPEUTIC X-RAYS

Chromosome painting by fluorescence in situ hybridization (FISH) with a whole chromosome-specific DNA probe was used to detect chromosomal a berrations in lymphocytes from cancer patients given partial-body frac tionated X-ray therapy. Six male patients with cancer of the stomach, prostate, lung, or hepatocellular carcinoma, received X-rays in total doses of 40.5 to 70.08 Gy. Lymphocytes were cultured for 50 h with phy tohemagglutinin. The mean frequency of aberrant cells detected by chro mosome 4 painting varied from 1.57% to 14.34% in the patients and was markedly higher than in healthy controls (mean=0.12%). Chromosome pain ting effectively detected chromosomal aberrations in lymphocytes from cancer patients. Equivalent biological doses extrapolated from a dose- response curve obtained in an in vitro human lymphocyte X-ray irradiat ion study are discussed as an indicator of the cytogenetic damage indu cible by radiotherapy in cancer patients.