In a report from the Children’s Oncology Group (COG) in the Journal of Clinical Oncology, McNeer et al found that hematopoietic stem cell transplantation (HSCT) did not improve outcomes in pediatric patients with hypodiploid B-lymphoblastic leukemia (B-ALL).
The study was a retrospective review of data from children and young adults with hypodiploid B-ALL enrolled in recent COG trials to evaluate the impact of HSCT on outcome. Cytogenetic analyses and DNA index were performed at COG-approved laboratories, with hypodiploidy being defined as modal chromosome number less than 44 and/or DNA index less than 0.81.
Outcomes With vs Without HSCT
Between 2003 and 2011, 8,522 patients with National Cancer Institute standard-risk and high-risk B-ALL were enrolled in COG protocols. Among these, hypodiploidy was diagnosed in 131 (1.5%). Complete remission after induction (CR1) was achieved in 98.3% of these patients. Among all patients with hypodiploidy, 5-year event-free and overall survival were 52.2% and 58.9%, respectively (compared with 85.2% and 91.8% among nonhypodiploid patients, P < .001 for both). Information on HSCT was not available for 18 patients in the hypodiploid cohort. Among 61 evaluable patients undergoing HSCT in CR1 vs 52 not undergoing HSCT in CR1, 5-year event-free survival was 57.4% vs 47.8% (P = .49) and 5-year overall survival was 66.2% vs 53.8% (P = .34).
Among patients with minimal residual disease of ≥ 0.01% at end of induction, 5-year event-free and overall survival were 26.7% and 29.3%, respectively. Among these patients, 5-year event-free survival (29.4% vs 16.7%, P = .67) and 5-year overall survival (29.4% vs 22.2%, P = .86) did not significantly differ between 18 patients undergoing HSCT vs 12 not undergoing HSCT.
The investigators concluded, “Children and young adults with hypodiploid B-ALL continue to fare poorly and do not seem to benefit from CR1 HSCT. This is especially true for patients with [minimal residual disease] of 0.01% or greater at the end of induction. New treatment strategies are urgently needed for these patients.”
Jennifer L. McNeer, MD, of the University of Chicago, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Institutes of Health, St. Baldrick’s Foundation, and Becton Dickinson Biosciences. The study authors' full disclosures can be found at jco.ascopubs.org.
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