Outcome of newly diagnosed children and adolescents with localized lymphoblastic lymphoma treated on Children's Oncology Group trial A5971: A report from the Children's Oncology Group

Background: Localized lymphoblastic lymphoma (LL) is rare in pediatric patients. We report the 5-year event-free survival (EFS) and overall survival (OS) for children and adolescents with localized LL treated on a uniform regimen based on Children's Cancer Group (CCG) leukemia therapy (COG A5971). Procedure: From June 2000 to October 2005, the study enrolled 60 patients >12 months old with Murphy stages I or II LL. Central review confirmed 56 eligible patients. Treatment consisted of 24 months of CCG BFM without day 28 intrathecal methotrexate in maintenance therapy or prophylactic cranial radiation. Results: Most patients had pre-B immunophenotype (75%). At a median follow-up of 5.9 years (range 1.4-9.3 years), the 5-year EFS was 90% [95% confidence interval (CI), 78-96%] and the 5-year OS was 96% (95% CI, 84-99%). Stage (I vs. II), immunophenotype, elevated LDH>institutional normal, or primary site did not impact outcome. Five relapses occurred-none in the CNS and none in patients with pre-T lymphoblastic disease. Patients tolerated treatment well with no toxic deaths. Conclusion: Outcomes of pediatric patients with localized LL treated with 2 years of intensive acute lymphoblastic leukemia (ALL)-type therapy was excellent and is similar to the outcome for standard risk ALL treated less intensively. CNS prophylaxis was adequate with limited intrathecal methotrexate and no radiation. Future studies should identify biologic prognostic factors or biomarkers for pediatric patients with LL, explore less intensive treatment for patients with localized disease, and explore novel immunophenotype directed therapies.