Abstract
Introduction: Slow rate of myeloid recovery at the end of induction chemotherapy reflected by a low absolute neutrophil count (ANC) is highly predictive of relapse in children with ALL (Laughton et al, 2005). Whether rate of myeloid recovery is predictive of outcome post-hematopoietic stem cell transplantation (HSCT) in children and young adults has not been studied.
Objective: To explore the association between early ANC recovery and survival in children and young adults undergoing allogeneic and autologous HSCT for leukemia or lymphoma.
Methods: Retrospective chart review was performed for all consecutive patients (age 6 months to 21 years) undergoing first HSCT for hematologic malignancies and lymphomas at Mayo Clinic, Division of Pediatric Hematology/Oncology from 1995 to 2004. Day 15 and day 28 ANC were calculated for all patients. The primary end point was 1-year relapse free (RFS) and overall survival (OS). To explore the association between ANC and primary outcome, patients were stratified in 2 groups: ≥ or < than median ANC and Kaplan Meier survival curves were generated for both the groups and compared with the log-rank test. Matched related donor (MRD), matched unrelated donor (MUD) and haploidentical (as one group) and autologous transplantations were analyzed separately.
Results: There were a total of 50 patients. 28 received MRD, 2 MUD, 10 haploidentical and 10 autologous. The underlying malignancies were (AML n =25, Biphenotypic Leukemia n=1, ALL n =7, NHL n=3, HD n=7, JMML n=5, CML n=2, CLL n=1). No patient was lost to follow up during that time and data was available for all except (day 28 ANC) for one patient. The 1-year RFS and OS rate was the same; 81% for the MRD, 50% for MUD and haploidentical and 70% for autologous transplant populations, respectively. In patients receiving MRD transplants, higher ANC at either day 15 or day 28 post transplantation was associated with better, albeit statistically non-significant, RFS/OS rates at 1 year (86% for ≥ median (0.68) vs. 76% for < median p=0.44 and 92% for ≥ median (2.2) vs. 72% for < median p= 0.18 respectively). Opposite results were observed for MUD and Haploidentical transplantation group (33% for ANC ≥ median (0.47) at day 15 vs. 66% for < median p=0.28, 43% for ANC ≥ median (1.9) at day 28 vs. 60% for < median p=0.48). For autologous transplant group, higher ANC at day 15 was associated with better, albeit statistically non-significant, RFS/OS rates at 1 year (80% for ANC ≥ median (0.42) vs. 60% for < median p=0.60) while opposite results were observed on day 28 (60% for ANC ≥ median (0.46) vs. 75% for < median p=0.54).
Conclusions: Our data generated conflicting findings of the association between ANC and RFS/OS in different patient populations undergoing HSCT. However, our results are limited by the small sample size. Further collaborative studies are needed to explore this association.
Late Endocrine Effects Remain Prevalent Despite Reduced Intensity Chemotherapy for Hematopoietic Stem Cell Transplantation in Children and Young Adults
