Utilization of radiation therapy in early-stage Hodgkin disease and its impact on survival

Abstract

8511 Background: Despite numerous randomized trials confirming the benefit of consolidation radiation therapy (RT) in the management of early stage Hodgkin disease (HD), utilization of RT in this setting remains variable. We performed a population-based analysis to assess the utilization of RT and its impact on overall and cause specific survival. Methods: The surveillance, epidemiology and end results (SEER) registry was used to identify patients aged 15–75 years diagnosed between 1990–2004 with early stage (stage I-IIA/B) HD, excluding nodular lymphocyte predominant HD. Kaplan-Meier analysis was performed to evaluate the effect of RT on overall survival (OS) and cause-specific survival (CSS). Subgroup survival analyses were also performed by era of treatment (1990–1997 and 1998–2004), sex, and patient age (<30, 30–50, and >50 years). Results: A total of 9729 patients met inclusion criteria. Median age of all patients was 34 years. The majority (71.3%) had nodular sclerosis (NS) type HD. By clinical stage, 3399 (34.9%) were stage I, and 6330 (65.1%) were stage II. 5352 patients (55%) received RT. RT was more likely to be employed during the early era of treatment, in younger patients, females, non-Blacks, and in NS, mixed cellularity and lymphocyte-rich HD. For the entire cohort, RT was associated with a significant (p<0.001) improvement in OS and CSS (hazard ratio of 0.537 and 0.437, respectively). The benefit of RT for OS and CSS remained significant for all subgroups analyzed including the era of treatment, sex, and age (p≤0.001). Conclusions: In this large population-based series of early stage HD patients, the use of RT is associated with a significant OS and CSS benefit across all subgroups. Current efforts in clinical trials have aimed at decreasing the utilization of RT among this patient population. This shift in practice is reflected in the data presented here. The omission of RT from the treatment paradigm, however, appears to be related with diminished survival. No significant financial relationships to disclose.