Características y valor de las aberraciones cromosómicas inducidas por los tratamientos antitumorales en pacientes pediátricos con cáncer

Cytogenetic studies were performed on 80 pediatric cancer patients to test the chromosomal damage induced by the chemotherapy treatments. G-banded karyotypes were performed on peripheral blood lymphocytes (PBL) (n=127) obtained at diagnosis, during treatment, at remission and at relapse. We detected a significant increase in the number of altered karyotypes in the samples during treatment, lowering to similar values to those at diagnosis at two year remission. Most of the chromosomal aberrations (CA) detected during chemotherapy were unbalanced (75%) and affected most frequently chromosomes 1, 3, 5, 6, 11, 12, 16 and 17. There was also a marked increase of CA in samples at relapse, with similar features (type and distribution) to those detected during treatment. There was an outstanding correlation between the chromosomal breakpoints in our series and fragile sites (58%), oncogene (75%) and tumour suppresor gene (33%) loci described in the literature. The results obtained suggest that the cytostatic drugs induce a transient increase in chromosome fragility that focuses to several cancer-associated breakpoints.