Sister chromatid exchanges and chromosome aberrations in children after treatment for malignant lymphoma.

Sister chromatid exchanges and chromosomal aberrations were investigated in lymphocytes from 11 children with malignant lymphoma after cessation of treatment. Chemotherapy combined with radiation was administered, terminating between 4 months and 13 years before chromosome analyses were performed. The frequency of sister chromatid exchanges per chromosome was the same, 0.20, in the patients and a matched control group, although there was a significant heterogeneity between individuals. The number of cells with chromosome abnormalities increased from 2.9% in control children to 4.8% in treated patients, a nonsignificant increase. Only translocations showed a significant increase.