Does bulky disease at diagnosis influence outcome in childhood Hodgkin's disease and require higher radiation doses?: Results from the German-Austrian Pediatric Multicenter Trial DAL-HD-90

Purpose: The identification of risk factors is required for risk-adapted treatment strategies in the treatment of Hodgkin's disease. To assess the influence of bulky disease at diagnosis as compared with other risk factors on event-free survival (EFS) in pediatric Hodgkin's disease such as stage, B-symptoms, number of involved lymph node regions, histology, and remission status after chemotherapy, we analyzed the outcome of 552 patients treated with a risk-adapted treatment strategy consisting of OPPA(OEPA)/COPP (vincristine, procarbazine, etoposide, prednisone, adriamycin, cyclophosphamide) and involved-field radiotherapy. Methods and Materials: Between 1990 and 1995, 578 patients with primary Hodgkin's disease (HD) were enrolled in the German/Austrian Pediatric Hodgkin's Disease Study Group (DAL) Multicenter Study (HD-90). Patients were stratified into three treatment groups (TGs) for early, intermediate, and advanced stage. All patients received induction chemotherapy (CT) with two cycles of OEPA for boys and two cycles of OPPA for girls. Patients in TG2 and TG3 received another two or four cycles, respectively, of COPP. Chemotherapy was followed by involved-field radiotherapy. The radiation field, which was prescribed by the study center, was treated with a dose of 25 Gy/25 Gy/20 Gy (TG1/TG2/TG3), and in case of insufficient remission with a local boost of 5 Gy to 10 Gy. The following prognostic factors were analyzed with regard to their impact on EFS: bulky disease, mediastinal tumor, number of involved lymph node regions, histology, treatment group, B-symptoms, sex, age, and remission status after chemotherapy. Results: Significant univariate predictive factors for EFS were: nodular sclerosis type 2 (NS2) histology (relative risk [RR] 3.43; p = 0.0002), presence of B-symptoms (RR 2.70; p = 0.0014), number of involved regions (1.55; p = 0.019), and treatment groups (RR 1.33; p = 0.017). There was a higher risk (RR 1.92; p = 0.040) for patients with bulky compared with nonbulky disease (5-year EFS 89.6%/94.6%). In the multiple regression model, only NS2 and B-symptoms remained strong predictive factors. The remission status after chemotherapy did not correlate with EFS (p = 0.66). Conclusion: Treatment strategies in Hodgkin's disease have an impact on different risk factors. In the risk-adapted treatment strategy of the HD-90 study, tumor burden indicated as bulky disease or as number of involved lymph nodes loses its importance, whereas NS2 histology and B-symptoms have a major impact on treatment outcome. Bulky disease at diagnosis might require higher radiation doses only in case of insufficient remission. (C) 2003 Elsevier Inc.