Treatment outcome of pediatric acute lymphoblastic leukemia in Yeungnam region: Multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology-Oncology (SAYPH)

AbstractObjectives: We aimed to evaluate treatment outcomes of pediatric acute lymphoblastic leukemia (ALL) subgroups by risk–stratification, in the Yeungnam region of Korea. Methods: We reviewed the courses of 409 newly diagnosed ALL patients from January 2004 to December 2013 in the Yeungnam region. Results: All patients were classified into three risk groups: standard risk (SR, n=212), high risk (HR, n=153) and very high risk (VHR, n=44). The mean follow-up time was 73.6 ± 39.4 months. The 7-year event-free survival (EFS) and overall survival (OS) rates were 78.7 ± 2.1% and 86.8 ± 1.8%, respectively. Significant 7-year EFS and OS rates for SR (84.0 ± 2.7%, 93.7 ± 1.8%), HR (76.5 ± 3.5%, 82.1 ± 3.3%), and VHR (60.6 ± 7.5%, 69.9 ± 7.5%) were observed (P<0.001), respectively. Relapse occurred in 52 patients, and the cumulative 7-year incidence of relapse differed according to risk groups (SR vs. HR vs. VHR=12.6% vs. 14.0% vs. 29.6%, P=0.003).For the 46 relapsed patients who were treated, the 3-year EFS an...