Outcomes in adolescents and young adults with Hodgkin lymphoma treated on US cooperative group protocols: An adult intergroup (E2496) and Children's Oncology Group (COG AHOD0031) comparative analysis

BACKGROUND: There is no clear consensus between pediatric and adult providers about the treatment of adolescents and young adults (AYAs) with Hodgkin lymphoma (HL). METHODS: Failure-free survival (FFS) and overall survival (OS) were compared between 114 patients ages 17 to 21 years with HL who were treated on the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Intergroup adult E2496 study and 391 similarly patients ages 17 to 21 years with HL who were treated on the pediatric Children's Oncology Group (COG) AHOD0031 study. RESULTS: Comparing AYAs from the COG and E2496 studies, there were no significant differences in extralymphatic disease, anemia, or hypoalbuminemia. More AYAs in the E2496 trial had stage III and IV disease (63% vs 29%; P < .001) and B symptoms (63% vs 27%; P < .001), and fewer had bulk disease (33% vs 77%; P < .001). More AYAs on the COG trial received radiotherapy (76% vs 66%; P = .03), although in smaller doses. E2496 AYA The 5-year FFS and OS rates were 68% and 89%, respectively in the E2496 AYAs and 81% and 97%, respectively, in the COG AYAs, indicating a statistically superior compared in the COG AYAs (P = .001). In stratified multivariable analyses, E2496 AYAs had worse FFS than COG AYAs in all strata except patients who had stage I and II HL without anemia. Propensity score analysis (based on stage, anemia, and bulk disease) confirmed inferior FFS for E2496 AYAs compared with COG AYAs (P = .004). On the E2496 study, FFS was significantly divergent across age groups (P = .005), with inferior outcomes for those ages 17 to 21 years versus 22-44 years. There was no difference across age on the COG study. CONCLUSIONS: Younger AYA patients with HL appear to have better outcomes when treated on a pediatric trial than patients of similar age on an adult trial. Prospective studies examining these differences are warranted. Cancer 2018;124:136-44. © 2017 American Cancer Society.