Effect of Treatment Modification by the Initial Response in Patients with High-Risk Childhood Acute Lymphoblastic Leukemia

Abstract

Background: The bone marrow (BM) findingd on day 7 of induction chemotherapy is one of major prognostic factors for patients with acute lymphoblastic leukemia (ALL). M3 marrow (blast ＞25% on BM examination) on day 7 is associated with lower survival rates, compared with the M1 (blast ＜5%) or M2 (blast 5∼25%) marrow. Herein, we analyzed the effect of augmented post-induction chemotherapy in patients who have high-risk ALL with M3 marrow on the day 7 BM examination. Methods: We analyzed the patients who were diagnosed with high-risk ALL and they received modified Children's Cancer Group (CCG)-1882 induction chemotherapy between January 1996 and October 2005 at Seoul National University Children’s Hospital. The patients with M1 or M2 marrow on day 7 were treated with modified CCG-1882A/B chemotherapy from consolidation, and the patients with M3 marrow were treated with modified CCG-1882C chemotherapy. Results: A total of 44 patients (29 with modified CCG-1882A/B and 15 with modified CCG-1882C) were analyzed. The overall survival (OS) and 5-year event-free survival (EFS) were 86.2% and 81.9%, respectively. The OS of the patients who were treated with the modified CCG-1882A/B protocol (88.9%) was not different from that of the patients who were treated with the modified CCG-1882C protocol (80.0%) (P=0.3256). Also, there was no statistical difference in the 5-year EFS of both groups (85.4% vs 72.7%, respectively, P=0.2117).Conclusions: There was no difference of survival between the patients with M1/M2 marrow on the day 7 BM examination and those with M3 marrow after augmented post-induction chemotherapy for the pa-tient with high-risk ALL. We suggest that the poor prognosis of high-risk ALL patients with a poor initial response could be overcome by augmented post-induction chemotherapy. (Korean J Hematol 2008;43:238-246.)