Outcomes of children, adolescents, and young adults following allogeneic stem cell transplantation for secondary acute myeloid leukemia and myelodysplastic syndromes-The MD Anderson Cancer Center experience

Outcomes with Allogeneic Hematopoietic Stem Cell Transplantation in Therapy Related Myeloid Neoplasms: A Systematic Review and Meta-Analysis

Therapy-related myeloid neoplasms (t-MN), which include acute myeloid leukemia (t-AML), myelodysplastic syndrome (t-MDS), and myelodysplastic/myeloproliferative neoplasms are secondary malignancies occurring as a late complication following chemotherapy or radiation therapy for an antecedent disorder. Allogeneic hematopoietic stem cell transplant (allo-HCT) is a potentially curative treatment option in t-MN patients. This systematic review and meta-analysis aimed to explore the outcomes of allo-HCT in t-MN. Following PRISMA guidelines, a comprehensive literature search was performed on PubMed, Cochrane, and Clinicaltrials.gov. Survival data were extracted from Kaplan-Meier curves to calculate overall survival (OS) and disease-free survival (DFS) probabilities. A total of 7785 (t-AML: 67.3%, t-MDS: 26.5%, and mixed presentation: 6%) patients from 33 original studies reporting outcomes of allo-HCT in t-MN patients were included for analysis. The patients age ranged from 2 to 89 years, and 61.7% were female. The pooled median OS was 16.9 months (95% CI: 13.7-21.1), whereas the estimated mean OS was 46.0 months (95% CI: 42.1-49.6). The pooled median DFS was 8.8 months (95% CI: 7.4-11.2), and the mean DFS was 35.5 months (95% CI: 33.4-41.9). The pooled proportion of acute graft-versus-host disease (aGvHD) was 34% (95% CI: 0.35-0.45, I²: 91.71%, P < .0001). Relapse of the myeloid neoplasm was the most common cause of mortality, followed by infections, relapse of the underlying disease, and GvHD. Despite these challenges, allo-HCT remains a potential treatment option with promising outcomes for carefully selected t-MN patients.

Treatment of recurrent pediatric myelodysplastic syndrome post hematopoietic stem cell transplantation

Treatment of recurrent myelodysplastic syndrome (MDS) after hematopoietic cell transplantation (HCT) remains challenging. We present a 4-year-old girl experiencing early MDS relapse post-HCT treated with a multimodal strategy encompassing a second HCT and innovative targeted therapies. We underscore the potential of a comprehensive treatment approach in managing recurrent pediatric MDS.

The effect of N-acetyl-l-cysteine (NAC) on liver toxicity and clinical outcome after hematopoietic stem cell transplantation

Busulphan (Bu) is a myeloablative drug used for conditioning prior to hematopoietic stem cell transplantation. Bu is predominantly metabolized through glutathione conjugation, a reaction that consumes the hepatic glutathione. N-acetyl-l-cysteine (NAC) is a glutathione precursor used in the treatment of acetaminophen hepatotoxicity. NAC does not interfere with the busulphan myeloablative effect. We investigated the effect of NAC concomitant treatment during busulphan conditioning on the liver enzymes as well as the clinical outcome. Prophylactic NAC treatment was given to 54 patients upon the start of busulphan conditioning. These patients were compared with 54 historical matched controls who did not receive NAC treatment. In patients treated with NAC, aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) were significantly (P < 0.05) decreased after conditioning compared to their start values. Within the NAC-group, liver enzymes were normalized in those patients (30%) who had significantly high start values. No significant decrease in enzyme levels was observed in the control group. Furthermore, NAC affected neither Bu kinetics nor clinical outcome (sinusoidal obstruction syndrome incidence, graft-versus-host disease and/or graft failure).

IN CONCLUSION

NAC is a potential prophylactic treatment for hepatotoxicity during busulphan conditioning. NAC therapy did not alter busulphan kinetics or affect clinical outcome.

How I treat myelodysplastic syndromes of childhood

Pediatric myelodysplastic syndromes (MDSs) are a heterogeneous group of clonal disorders with an annual incidence of 1 to 4 cases per million, accounting for less than 5% of childhood hematologic malignancies. MDSs in children often occur in the context of inherited bone marrow failure syndromes, which represent a peculiarity of myelodysplasia diagnosed in pediatric patients. Moreover, germ line syndromes predisposing individuals to develop MDS or acute myeloid leukemia have recently been identified, such as those caused by mutations in GATA2, ETV6, SRP72, and SAMD9/SAMD9-L Refractory cytopenia of childhood (RCC) is the most frequent pediatric MDS variant, and it has specific histopathologic features. Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for many children with MDSs and is routinely offered to all patients with MDS with excess of blasts, to those with MDS secondary to previously administered chemoradiotherapy, and to those with RCC associated with monosomy 7, complex karyotype, severe neutropenia, or transfusion dependence. Immune-suppressive therapy may be a treatment option for RCC patients with hypocellular bone marrow and the absence of monosomy 7 or a complex karyotype, although the response rate is lower than that observed in severe aplastic anemia, and a relevant proportion of these patients will subsequently need HSCT for either nonresponse or relapse.