Chromosomal aberrations detected by chromosome painting in lymphocytes from cancer patients given high doses of therapeutic X-rays.

Abstract

Chromosome painting by fluorescence in situ hybridization (FISH) with a whole chromosome-specific DNA probe was used to detect chromosomal aberrations in lymphocytes from cancer patients given partial-body fractionated 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 phytohemagglutinin. The mean frequency of aberrant cells detected by chromosome 4 painting varied from 1.57% to 14.34% in the patients and was markedly higher than in healthy controls (mean = 0.12%). Chromosome painting 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 irradiation study are discussed as an indicator of the cytogenetic damage inducible by radiotherapy in cancer patients.