Abstract:

Abstract Aim: Despite numerous advances in treating acute lymphoblastic leukemia (ALL) in children, relapse continues to be the leading cause of mortality. This study aimed to analyze the data of patient’s characteristics, and outcomes of children with relapsed ALL. Material and Method: We retrospectively analyzed the records of patients aged 1–18 years diagnosed with relapsed ALL between January 2004 and December 2018. Results: 452 ALL patients followed up in the study period and 55 patients relapsed. The relap-se rate was 12.1%. Thirty-four (61.8%) of the relapsed patients were male. The median age was seven years (1–17 years). Forty-six patients (83.6%) had precursor B-cell ALL and nine pati-ents (16.3%) had T-cell ALL. The site of relapse was bone marrow in 41 patients (74.5%), and extramedullary (central nervous system, testis, or soft tissue) in 11 patients (20%). The mean duration from the initial diagnosis to relapse was 32 months ( min-max: 4 -108 months, SD±21.2) and 20 months (min-max: 7-38 months, SD± 11.1) in patients with B- cell ALL and T- cell ALL respectively. The median follow-up time was 39.8 months (min-max: 3–198 months, SD±44.5) from the initial diagnosis. Thirty-seven patients (67.3%) died. The 5-year overall survival rate was 41.6%. Recurrent relapse and progressive disease were the most com-mon causes of death. The mortality rate was significantly associated with the immunophenotype, treatment response on days 8, 15, and 33 of initial diagnosis, the risk group at initial diagnosis, the site of relapse, and hematopoietic stem cell transplantation (p<0.05). Immunophenotype and the site of relapse were the independent variables associated with mortality. Conclusion: Relapse affects a significant portion of patients with ALL. Survival rates are still poor in patients with relapsed ALL. Also, our findings that T-cell immunophenotype and the site of relapse (isolated bone marrow relapse) were independent risk factors for mortality sug-gest that more specialized treatment options are needed for patients with T-ALL and bone mar-row relapse.

Keywords: