[Cytogenetic risk categories in acute myeloid leukemia: a comparison between MRC (Medical Research Council) and SWOG (Southwest Oncology Group) models)].
OBJECTIVE
Classification of acute myeloid leukemia (AML) based on karyotype provides an important tool for therapy selection. There are two standardized criteria for the classification of patients into groups of cytogenetic risk. One of them was established by the UK Medical Research Council (MRC) and the other by the US Southwest Oncology Group (SWOG). They define three and four cytogenetic categories, respectively. The aim of this study was to define the frequency of chromosomal abnormalities and to compare the groups of cytogenetic risk in patients with AML who received intensive chemotherapy, as a guide for future investigations.


METHODS
Chromosomal analysis was performed using standard techniques on bone marrow samples from 146 adult patients between January 1995 and December 2001. Kaplan-Meier and Cox's regression models were used for statistical analysis.


RESULTS
Cytogenetic results were obtained in 142 patients. The incidence of a complex karyotype and del(5q) was higher in patients with secondary AML. Classification by cytogenetic risk was performed in 105 treated patients. The classification using both models was identical in 82 patients and different in 23. Results in univariate analysis were significant for EFS (p < 0.000 for MRC and p < 0.02 for SWOG). Nevertheless, only the MRC model was significant for OS (p < 0.001). In multivariate analysis, age and cytogenetics were the only variables having prognostic value.


CONCLUSIONS
There was some relation between secondary AML, advanced age and adverse karyotype. Both classification models have a great prognostic value. In our experience, codification according to MRC criteria appears to be more effective to detect patients at high risk of relapse.
Martín Ramos
María Luisa
ML
Servicios de Genética y Hematología. Hospital Universitario 12 de Octubre. Madrid. Spain. mmartinr.hdoc@salud.madrid.org
López Pastor
Margarita
M
de la Serna Torroba
Javier
J
Ayala
Rosa
R
García Alonso
Luis
L
Barreiro Miranda
Emilia
E
D000208:Acute Disease; D002869:Chromosome Aberrations; D006801:Humans; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000145:classification / Q000188:drug therapy / Q000235:genetics*; D011379:Prognosis; D016019:Survival Analysis