Persistent chromosomal aberrations in somatic cells in testicular cancer patients after different therapies

Abstract

Background. The damage due to radiation or chemotherapeutic agents has been estimated successfully for the last 35 years from the numbers of the chromosome changes. This finding may serve as biological dosimeter. The aim of the study was to find persistent chromosomal aberrations in somatic cells in testicular cancer patients after different therapies.

Patients and methods. This prospective study includes 60 patients with testicular tumours. With respect to the histological results and various therapies that they were given they were divided into four groups. Prior to treatment, we did not detect any deviations either in the genome picture of our patients or in that of the subjects of the control group without malignant disease. The changes in the genome of individual cells after therapy were detected by the following tests: structural chromosomal aberrations (SCA) test, sister chromatid exchange (SCE) test and micronucleus (MN) test performed on binuclear lymphocytes.

Results. Immediately after the completion of treatment, chromosomal aberrations were inhibited, with the exception of dicentrics which persisted. Chemotherapy is less detrimental to the genome picture than radiotherapy and causes different types of chromosome changes. From the cytologic and mutagenetic points of view, irradiation proved to be more aggressive to patients than chemotherapy. Six months after the completed treatment, the mitotic activity was found to be nearly normal; but the chromosome damage persisted and was higher than before therapy and in the fourth group of patients who had been only operated on.

Conclusions. After irradiation as well as after chemotherapy the genome was repaired, because the damaged cells had died away. Considering that in the observed patients, only small tissue-cellular complex responded to radiation and that the number structural chromosome changes, predominantly unstable aberrations, such as dicentrics, was rather high, we assume that the repair of the genome will be faster in these patients.