PROGNOSIS IN ACUTE LYMPHOBLASTIC LEUKEMIA: IMPORTANCE OF CHROMOSOME STUDY

The rule of clonal chromosomal aberrations, either numerical or structural, has been proved in childhood acute lymphoblastic leukemia (all). some of these abnormalities could be used as diagnostic and/or prognostic parameters. aim of the present investigation was to report the importance of chromosomal aberrations as a prognostic factor in all patients. thirty seven children affected with all were cytogenetically investigated at diagnosis and all through different stages of the disease (remission and relapse). a clonal karyotypic abnormality was found in 23 patients at diagnosis (mainly comprised of calla+). a hyperdiploid mode with chromosome counts ranging from 47-58 was found to be the most prominent among calla+ patients. the most common numerical aberrations were gain of chromosomes 2, 5, and 21. the structural aberrations at diagnosis were found to be del (9) (p22), inv (9) (p ii q 13) and del (19) (p 12). none of the children showed ph+ chromosome. a good prognosis was found in calla+ children with an abnormal karyotype at diagnosis and of these children, those who showed karyotypic instability had a significantly longer first remission time. the karyotypic evolution through remission(s) and relapse(s) revealed the occurrence of structural alterations, including chromosomes 3, 6, 9, 21 and 22. however, irrespective of the karyotypic clonal nature at diagnosis, chromosome 9 was considered as a common involved chromosome through the course of disease