Early-Stage Classical Hodgkin Lymphoma: The Utilization of Radiation Therapy and Its Impact on Overall Survival
Menée à partir des données du registre national américain des cancers portant sur 29 752 patients atteints d'un lymphome hodgkinien classique de stade I/II diagnostiqué entre 1998 et 2011, cette étude évalue l'effet d'une radiothérapie de consolidation sur la survie globale des patients
Purpose : Treatment for early-stage classical Hodgkin lymphoma (HL) includes combined modality therapy (CMT) of chemotherapy followed by consolidation radiation therapy (RT), but use of RT has not been universal. We examined the association between RT utilization and overall survival for patients with early-stage HL. Methods and Materials : Using the National Cancer Database (NCDB), we evaluated clinical features and survival outcomes among patients diagnosed with Stage I/II HL from 1998 to 2011. The association between RT use, co-variables, and outcome was assessed in a Cox proportional hazards regression model. Propensity score (PS) matching was performed to balance observed confounding factors. Survival was estimated using the Kaplan-Meier method. Results : Among the 41,943 patients in the NCDB with Stage I/II HL, 29,752 patients were analyzed for this study. RT use was associated with younger age (≤40 years), favorable insured status, higher socioeconomic status (income, education), and treatment at comprehensive community cancer centers (all p<0.05). Five-year overall survival for patients receiving RT was 94.5% versus 88.9% for those not receiving RT (p<0.01). RT use was a significant predictor of overall survival in the as-treated cohort (HR=0.53; 95% CI, 0.49-0.58, p<0.01) and intention to treat analysis (p<0.01). After PS-matching based on clinicopathologic characteristics, RT use remained associated with improved overall survival (HR=0.46; 95% CI, 0.38-0.56, p<0.01). Over the study period, RT utilization for this cohort decreased from 55% to 44%, most commonly because it was not part of the planned initial treatment strategy. Conclusion(s) : Consolidation RT was associated with improved OS for patients with early-stage classical HL. We also have identified patient-specific variations in the use of RT that may be targeted to improve patient access to care.