Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for juvenile myelomonocytic leukemia (JMML), but few large studies of HSCT for JMML exist. Using data from the Japan Society for Hematopoietic Cell Transplantation registry, we analyzed the outcomes of 129 children with JMML who underwent HSCT between 2000 and 2011. The 5-year overall survival (OS) rate and cumulative incidence of relapse were 64% and 34%, respectively. A regimen of busulfan/fludarabine/melphalan was the most commonly used (59 patients) and provided the best outcomes; the 5-year OS rate reached 73%, and the cumulative incidences of relapse and transplantation-related mortality were 26% and 9%, respectively. In contrast, the use of the irradiation-based myeloablative regimen was the most significant risk factor for OS (hazard ratio [HR], 2.92; P = .004) in the multivariate model. In addition, chronic graft-versus-host disease (GVHD) was strongly associated with lower relapse (HR, 0.37; P = .029) and favorable survival (HR, 0.22; P = .006). The current study has shown that a significant proportion of children with JMML can be cured with HSCT, especially those receiving the busulfan/fludarabine/melphalan regimen. Based on the lower relapse and better survival observed in patients with chronic GVHD, additional treatment strategies that focus on enhancing graft-versus-leukemia effects may further improve survival.
Recent studies have demonstrated the protective effect of cytomegalovirus (CMV) reactivation against relapse after allogeneic hematopoietic stem cell transplantation (HSCT) for adult myeloid malignancies. We assessed the association of CMV reactivation, defined as the development of CMV antigenemia (at least 1 pp65 antigen-positive cell per 5.0 × 10(4) WBCs) within 100 days after HSCT, with the risk of relapse in 143 patients with pediatric acute leukemia. The median age at HSCT was 7 years, and underlying diseases included acute lymphoblastic leukemia in 101 patients and acute myeloid leukemia in 42. The cumulative incidence of CMV reactivation at day 100 after HSCT was 45.4%. At a median follow-up of 88 months, patients with CMV reactivation had significantly lower 5-year cumulative incidence of relapse compared with patients without CMV reactivation. In a multivariate analysis, high-level CMV reactivation (≥10 pp65 antigen-positive cells) was an independent factor associated with reduced relapse. However, CMV reactivation was also associated with higher nonrelapse mortality (NRM), mostly caused by opportunistic infection after grades II to IV acute graft-versus-host disease (GVHD), which resulted in decreased probability of survival. High-level CMV reactivation was a risk factor for increased NRM and worse overall survival in multivariate analysis. Although CMV reactivation may reduce the risk of relapse after HSCT for pediatric acute leukemia, effective management of severe acute GVHD and better prophylaxis and treatment of opportunistic infections are required to reduce the incidence of NRM and improve survival. Further studies on pediatric HSCT that include a larger number of patients and more homogenous patient cohorts are desirable.
Hematologic stem cell transplantation (HSCT) is the most potent consolidation therapy for high-risk acute lymphoblastic leukemia (ALL), but their outcomes and complications in adolescent and young adult (AYA) patients remain unclear. We compared outcomes after HSCT for ALL among children (age 1 to 9 years; n = 607), adolescents (age 10 to 19 years; n = 783), and young adults (age 20 to 29 years old, n = 603), based on Japanese nationwide registry data. The 5-year overall survival (OS) rate among AYA patients was worse than that of children, at 64% (95% confidence interval [CI], 60% to 68%). In the AYA, the 5-year treatment-related mortality (TRM) after HSCT was 19% (95% CI, 16% to 22%), significantly higher than that in younger patients. The most common cause of TRM in the AYA was infection. The relapse rate was not different across the 3 age groups. When focusing on older adolescents (age 15 to 19 years), there was no difference in outcomes between those treated in pediatric centers and those treated in adult centers. In conclusion, the AYA had a greater risk of nonrelapse death than younger patients, and infection was the most common cause. Further optimization is required for HSCT in AYAs with ALL.
We report the long-term morbidity and mortality of 105 pediatric patients who developed chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). According to the consensus criteria of the National Institutes of Health, the global severity of cGVHD was mild in 26 patients (25%), moderate in 30 patients (29%), and severe in 49 patients (47%). Patients with severe cGVHD had a significantly lower cumulative incidence of cGVHD remission and higher probability of continuing cGVHD at 8 years from cGVHD diagnosis compared with those with mild or moderate cGVHD. The 10-year cumulative incidence of nonrelapse mortality in severe cGVHD patients was significantly higher and the probability of disease-free survival was significantly lower than those among patients with mild and moderate cGVHD. Of the 59 patients who survived for more than 5 years, 20 (34%) (4 with moderate and 16 with severe cGVHD) had persistent functional impairment caused by cGVHD with a Karnofsky/Lansky performance score of 90% in 3 patients, 80% in 4 patients, and below 70% in 13 patients at the time of relapse, death, or last follow-up. Better therapeutic strategies are needed to lower the incidence of severe cGVHD, considering the longer life expectancy of pediatric HSCT survivors.
A standard treatment is yet to be established for steroid-refractory acute aGVHD following HSCT. The effects of MMF have not been well studied in children with aGVHD. We evaluated the effectiveness of oral MMF in 14 children with steroid-refractory aGVHD (grade II in one patient, grade III to IV in 13 patients). The median initial dose of MMF was 40 mg/kg/day (range, 30-74) and was increased by 1.5-2 times if manifestations of GVHD did not improve. Within four wk of treatment, seven patients (50%) achieved CR, and four (29%) had a PR. Within eight wk, 11 patients (79%) achieved CR without using additional agents. Overall, 12 patients are alive and in remission with a median follow-up of 35 months (range, 14-86). The median maximum dose of MMF was 60 mg/kg/day (range, 34-107). No fatal toxicity was observed, including MMF-related infections. MMF appears to be highly effective for steroid-refractory aGVHD when used at a higher dose than has been described previously. Larger studies and pharmacokinetic analysis are required to evaluate its efficacy and toxicity and find the optimal dose of MMF in children.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.