Treatment outcome in young adults and children >10 years of age with acute lymphoblastic leukemia in Sweden

Abstract

Several studies have reported a more favorable outcome for teenagers and young adults with acute lymphoblastic leukemia (ALL) when they were treated in pediatric oncology departments compared with adult hematology departments. However, biased risk grouping and high treatment-related mortality have hampered some of those comparisons. In Sweden during the 1990s, adolescents with ALL were treated in a pediatric oncology unit or in an adult hematologic unit, depending on the initial referral. In the current national, comparative, retrospective study, patients with ALL aged 10 years to 40 years who were treated either according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL protocol (1992-2000) (NOPHO-92 protocol) or according to the Swedish Adult ALL Group protocol (1994-2000) (Adult protocol) were included. None of the protocols had age as a high-risk criterion. In total, 243 patients with B-precursor and T-cell ALL were treated according to the protocols. There was a significant difference in the remission rate between the NOPHO-92 protocol (99%; n = 144 patients) and the Adult protocol (90%; n = 99 patients; P < .01), and the event-free survival (EFS) was also superior for the NOPHO-92 protocol compared with the Adult protocol (P < .01). However, EFS was higher for patients aged 15 years to 25 years compared with patients aged 26 years to 40 years within the Adult protocol group (P = .01). The treatment protocol itself was identified as an independent risk factor. The NOPHO-92 protocol resulted in a better outcome than the Adult protocol; therefore, adolescents may benefit from the pediatric protocol treatment strategy. Prospective trials are warranted to determine whether young adults would benefit from similar treatment.