Treatment Outcomes for Children With Hypodiploid Acute Lymphoblastic Leukemia
In a retrospective study reported in the Journal of Clinical Oncology, Pui et al found that minimal residual disease (MRD)-negative status, high hypodiploidy with 44 chromosomes, and MRD-stratified treatment were associated with improved outcomes among children treated for newly diagnosed hypodiploid acute lymphoblastic leukemia (ALL). Allogeneic hematopoietic cell transplantation (HCT) did not improve outcomes compared with chemotherapy alone.
Study Details
The study included data on 272 evaluable patients aged ≤ 21 years enrolled in the protocols of 16 cooperative study groups or institutions between 1997 and 2013. Clinical and biologic characteristics, early therapeutic responses as determined by MRD assessment, treatment with or without MRD-stratified protocols, and allogeneic HCT were analyzed for impact on outcome.
Treatment Outcomes
Median follow-up was 6.6 years. Among all patients, 5-year event-free survival was 55.1% and 5-year overall survival was 61.2%. In univariate analysis, rates of 5-year event-free survival were improved in patients with negative MRD at the end of remission induction (75%), high hypodiploidy with 44 chromosomes (74%), and treatment in MRD-stratified protocols (62%).
In multivariate analysis, high hypodiploidy with 44 chromosomes vs near haploidy (hazard ratio [HR] = 0.39, P = .014,) and treatment with vs without MRD-stratified protocols (HR = 0.48, P = .005) were associated with a significant benefit in event-free survival; similar results were observed for overall survival.
In analysis excluding patients with high hypodiploidy with 44 chromosomes and adjusting for waiting time to transplantation and other covariates, there was no significant difference in disease-free survival between 42 patients who underwent transplantation and 186 patients who received chemotherapy only (5-year rate = 59% vs 51.5%, P = .16). Five-year adjusted disease-free survival did not differ between patients receiving transplantation and those receiving chemotherapy alone among patients with MRD-negative status (P = .81) or among those with MRD-positive status (P = .29).
The investigators concluded, “MRD-stratified treatments improved the outcome for children with hypodiploid ALL. Allogeneic transplantation did not significantly improve outcome overall and, in particular, for patients who achieved MRD-negative status after induction.”
Ching-Hon Pui, MD, of the Department of Oncology, St. Jude Children’s Research Hospital, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by National Cancer Institute grants, Bloodwise, and American Lebanese and Syrian Associated Charities. The study authors' full disclosures can be found at jco.ascopubs.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
