Adolescents who have acute lymphoblastic leukemia (ALL) have better outcomes in pediatric trials than they do in adult trials, but survival is still poorer for adolescents than it is for younger patients in pediatric trials, according to trial results reported in Hematological Oncology.
The investigation was the prospective, randomized study in the European Organisation for Research and Treatment of Cancer clinical trial (EORTC CLG-58951; ClinicalTrials.gov Identifier, NCT00003728). Adolescents who were diagnosed as having ALL at age 15 to younger than 18 years were eligible to participate in the analysis; outcomes were analyzed for 97 patients (70 adolescents with B-lineage ALL and 27 adolescents with T-lineage ALL). Various aspects of treatment were compared, including a comparison of prednisone with dexamethasone in induction therapy.
Patients with B-lineage ALL had a complete response (CR) rate of 97.1% at the end of induction and an overall CR rate of 98.6%. A total of 11 patients with B-lineage ALL died. The 8-year event-free survival (EFS) rate was 72.3% (95% CI, 59.4%-81.7%), and the 8-year overall survival (OS) rate for this group was 80.8% (95% CI, 67.4%-89.1%). EFS and OS rates were similar between prednisone and dexamethasone treatments.
Patients with T-lineage ALL had CR rates of 77.8% after induction and 85.2% following consolidation. A total of 11 patients in this group died. The 8-year EFS rate was 57.4% (95% CI, 36.1%-74.0%), and 8-year OS was 59.0% (95% CI, 36.1%-76.2%). With prednisolone, the 8-year EFS for this group was 51.4% (95% CI, 23.8%-73.5%), and with dexamethasone it was 65.6% (95% CI, 32.0%-85.6%), but OS rates remained similar between these treatments.
The study investigators noted that, across studies in ALL, adolescent patients show worse outcomes than are seen with children younger than 15 years. However, adolescents on pediatric trials tend to show improved prognosis compared with adolescents on adult trials.
The investigators suggested that poorer outcomes for adolescents than younger children may involve drug resistance, possibly a different set of genetic aberrations in leukemic cells, and potential differences in treatment compliance.
“Several actions should be implemented to improve the prognosis of adolescent leukemias, notably a better characterization of molecular abnormalities, the use of innovative immunological treatment as well as improved supportive care,” concluded the investigators in their report.
Olivier-Gougenheim L, Arfeuille C, Suciu S, et al. Pediatric randomized trial EORTC CLG 58951: outcome for adolescent population with acute lymphoblastic leukemia. Hematol Oncol. Published online August 18, 2020. doi:10.1002/hon.2791