Výskyt a léčba relapsu dětské akutní lymfoblastickéleukémie v České republice v letech 1990–2000

The incidence and treatment of relapse of childhood acute lymphoblasticleukemia in the Czech Republic between 1990–2000

Successful treatment of relapsed acute lymphoblastic leukemia (ALL) is one of the biggest challengesin pediatric hematooncology at the beginning of the 21st century. The authors analyze a group of 85children suffering first relapse of ALL in the Czech Republic between 1990–2000. The probability of4-year event-free survival (EFS) was 16.7% (SE 5%) and that of overall survival 22.8% (SE 5%) for thewhole group. In the 1996 treatment of children with relapse of ALL was unified according to theGermanprotocol ALL-REZ BFM 96. Twenty-six (47.3%) out of 55 children achieving second remission weretreated by chemotherapy alone, 21 (38.2%) children underwent allogeneic stem-cell transplantation(SCT), and 8 patients (14.5%) autologous SCT. Very early and early relapses were diagnosed in 78.8% ofthe patients. EFS was 6.7% and 18.2% for children with very early and early relapse, respectively.Significantly better results were achieved in children with late relapses (EFS 37.8%). Isolated bonemarrow relapse was the most frequent type of disease recurrence (70.6%) characterized by a pooroutcome (EFS 11.5%). On the other hand, more than half of boys with isolated testicular relapse werecured. SCT did not improve the prognosis of children with very early and early relapses significantly.Late relapse is heterogenous disorder. SCT has a key role in the management of selected groups ofpatients. For the entire group of children with late relapses the results of SCT and chemotherapy werecomparable. The best treatment strategy lies in prevention of relapse through effective initial therapyof leukemia and individualization of the treatment plan according to the level of minimal residualdisease.

Key words:
acute lymphoblastic leukemia, relapse, children, stem-cell transplantation, chemotherapy,BFM protocol