Similar outcomes between adolescent/young adults and children with AML following allogeneic hematopoietic cell transplantation

Abstract

We recently reported that adolescents and young adults (AYAs) with B-cell ALL receiving allogeneic hematopoietic cell transplantation (allo-HCT) have inferior survival compared with children, primarily because of greater TRM. We therefore hypothesized that in the setting of allo-HCT for AML, similar inferior outcomes would be observed in AYA patients as compared with children. We reviewed outcomes of 168 consecutive patients (ages 0-30 years) with AML undergoing allo-HCT at our institution. Of these, 60% (n ¼ 101) were o15 years of age and 40% (n ¼ 67) were AYAs (15-30 years of age). We identified no significant differences in 5-year overall survival (48% vs 50%, P ¼ 0.89), disease-free (47% vs 47%, P ¼ 0.89), relapse (24% vs 33%, P ¼ 0.30) or TRM (27% vs 16%, P ¼ 0.10) between the two groups. However, AYA patients had a greater incidence of grade II-IV acute (48% vs 31%, P ¼ 0.01) and chronic GVHD (22% vs 7%, Po0.01). Based on this analysis we identified no differences in survival, relapse or TRM between AYAs and children with AML receiving allo-HCT. INTRODUCTIONGradual improvements in the survival of patients with newly diagnosed AML have been achieved through treatment intensification; 1,2 however, differences in outcomes continue to exist between adolescents and young adults (AYAs) and younger-aged children. 3,4 Although overall survival appears to be similar between these two age groups (children o15 years of age vs AYAs), there are stark differences in chemotherapy-related mortality, with AYA patients having significantly higher rates of treatment-related deaths most often from infection. 3,4 The reasons why AYA patients may have significantly worse outcomes compared with younger children include: age-related differences in the underlying cancer biology; 5 access to medical care; 6 compliance with treatment, 7 participation in clinical trials 8 and/or not receiving care at centers with AYA experience. 7,9 We recently investigated survival differences between AYA patients and younger-aged children (o13 years of age) with B-cell ALL who received allogeneic hematopoietic cell transplantation (allo-HCT) at our institution and found significantly inferior survival in the AYA group. 10 These findings were primarily because of greater TRM in AYA patients. Based on these results and the higher mortality recently reported in chemotherapy-treated AYA AML patients, 3,4 we hypothesized that AML AYA patients undergoing allo-HCT would have inferior outcomes as compared with younger patients.

Outcome of adolescent patients with acute myeloid leukemia treated with pediatric protocols

“…There is a large retrospective study using CIBMTR database showing [27]. However, the University of Minnesota reported that their allogeneic HSCT results did not differ between children (0-14 years old) and AYA (15-30 years old) in terms of TRD, OS, diseasefree survival, and relapse [28]. Because no toxic event was observed among the six patients who underwent HSCT initially planned in the first remission in our study, we suppose that the high TRD of adolescent patients after salvage therapy cannot be attributed only to HSCT itself.…”

Unique Challenges of Hematopoietic Cell Transplantation in Adolescent and Young Adults with Hematologic Malignancies

“…However, rates of chronic GVHD are significantly higher in adults compared with children [62]. Multiple studies have shown higher rates of acute GVHD in AYAs than in children, although the rates of chronic GVHD in these groups remain unclear [63,64]. An important area where significant progress has been made over the last decade and is relevant to AYAs is that of biomarkers.…”

Allogeneic Hematopoietic Stem Cell Transplantation for Adolescents and Young Adults with Acute Myeloid Leukemia

“…However, the data on AML are very limited [3] and only a few retrospective studies of AYA patients with AML have compared pediatric and adult approaches [4][5][6][7][8][9]. Although allogeneic hematopoietic stem cell transplantation (HSCT) is an important curative option for both children and adults with AML, only a few reports have examined the procedure in AYA patients with AML [10,11]. Furthermore, AYA patients, especially adolescents, may undergo transplantation at either a pediatric or an adult transplantation center, depending on their referral pattern, and the differences in practices and attitudes between pediatric and adult physicians might influence HSCT outcomes.…”