Treatment patterns and outcomes in adolescents and young adults with nodular lymphocyte‐predominant Hodgkin lymphoma: an IMPACT cohort study.

Summary: We leveraged population‐based clinical and healthcare data to identify treatment patterns and long‐term outcomes among adolescents and young adults (AYA) with nodular lymphocyte‐predominant Hodgkin lymphoma (NLPHL). All Ontario, Canada, AYA aged 15–21 years at diagnosis with NLPHL between 1992 and 2012 were identified, and their detailed clinical data were collected. Linkage to healthcare databases identified additional events (subsequent malignant neoplasms [SMN], relapses and deaths). Event‐free survival (EFS) and overall survival (OS) were compared by locus of care (adult vs. paediatric) and predictors of outcomes determined. Of 1014 AYA with Hodgkin lymphoma, 54 (5.3%) had NLPHL; 15 (27.8%) were treated at a paediatric centre. No paediatric centre patient received radiation only versus 16 (41.0%) of adult centre patients. Excision only was more common in paediatric centres (p < 0.001). The 20‐year EFS and OS rates were 82.9% ± 5.2% and 100% respectively. Advanced stage (hazard ratio: 4.9, 95% CI: 1.3–18.4; p = 0.02) was associated with inferior EFS. Although the 25‐year cumulative incidence of SMN was 19.3% ± 9.6% for the entire cohort, there were no SMN among the patients treated with excision only. AYA with NLPHL have outstanding long‐term survival. Resection alone was rare outside of paediatric institutions but associated with excellent outcomes. Given substantial SMN risks, chemotherapy‐sparing and radiation‐sparing strategies for appropriate subsets of patients are warranted. [ABSTRACT FROM AUTHOR]