Validação do Escore de Risco do EBMT em 1.084 pacientes portadores de leucemia mielóide crônica submetidos ao transplante alogênico de células precursoras hematopoiéticas no Brasil

Abstract

Abstract This study is a retrospective analysis of 1084 patientstransplanted in ten Brazilian centers in the period fromFebruary 1983 to March 2003. The main objective was tovalidate the EBMT risk score in chronic myeloid leukemiapatients submitted to allogeneic hematopoietic stem celltransplantation.The risk score is based on five variables: recipientage, disease stage, donor type [HLA-identical related,matched unrelated or unmatched donor], donor-recipientgender combination, and interval from diagnosis totransplantation. The total of the points allocated to eachof the different criteria stratifies the patients in risk scoregroups of from zero to seven.The mean age of the evaluated patients in this studywas 33 years old (from 6 to 58 years), with 647 (59.7%)male and 437 (40.3%) female. At the time of transplantation,898 (82.8%) were in the chronic phase, 146 (13.5%) in theaccelerated phase and 40 (3.7%) in the blastic phase. Onehundred and fifty-one (13.9%) of the patients were under20 years old, 620 (57.2%) between 20 and 40 years old and313 (28.9%) were older than 40. The transplantation wasHLA-identical related in 1025 (94.6%) of the recipients andnon-related in only 59 (5.4%) of the cases. The donor-recipient gender combination was female into male in 283(26.1%) of the transplantations, whilst other combinationsoccurred in 801 (73.9%) cases. The interval from diagnosisto transplantation was less than 12 months in 223 (20.6%)patients and greater than 12 months in 861 (79.4%). In 179(16.6%) patients, the risk score was 0 or 1, in 379 (36.6%)the score was 2, in 345 (31.8%) it was 3, in 135 (12.5%) itwas 4 and in the remaining 28 cases (2.6%) the score was5 or 6. There were no cases with a score of 7.The overall survival rate was 49.23% at a median of67 months. The disease free survival rate was 50.36%, thetransplant-related death rate was 45.18% and the incidenceof relapse was 24.66%.Patients with risk scores of 0 and 1 or 2 in relation tothe overall survival rate did not present with significantdifferences (58.5% - 55.4%: Relative Risk 19). The overallsurvival rate was significant in relation to risk score of 3and greater (44.3%: Relative Risk 53). The criterion, diseasestage, was considered significant. The chronic phase gavean overall survival rate of 54.7%; the accelerated phase27.7% (relative risk of 81) and the overall survival rate inthe blastic phase was 14% (relative risk of 211). The donor-recipient gender combination was also significant with anoverall survival rate of 40.5% (relative risk 33) when thetransplant was female into male. Other combinationspresented with a rate of 52.4%. There were no significantdata of overall survival in relation to the other three criteria.The risk score was significant in respect to thedisease free survival, transplant-related death with scoresof 3 and higher, and incidence of relapse with scores of 5or 6 with values of 45.6%, 48.9% and 73.3% respectively.In isolation, the disease phase was significant in the threeparameters and donor-recipient gender combination onlyin relation to disease free survival and transplant-relateddeath. The results indicate that the potential of overallcure of patients submitted to transplantation isapproximately 50%, and that the EBMT score as it wasdesigned is a decision making tool for indication oftransplantation. Additionally, the results identify thedisease stage and the donor-recipient gender combinationas the two most important independent criteria. With theresults of this independent study, we can confirm that theEBMT risk score for chronic myeloid leukemia is valid andshould be used for clinical decision making whenindicating transplantation.