Further chemotherapy versus low-dose involved-field radiotherapy as consolidation of complete remission after six cycles of alternating chemotherapy in patients with advanced Hodgkin's disease

Abstract
It was the aim of this prospective randomized multicenter study to compare chemotherapy and radiotherapy as consolidation treatments in patients achieving complete remission (CR) after 6 cycles of doxorubicin-containing chemotherapy in advanced-stage Hodgkin's disease (HD). A total of 288 previously untreated patients aged 18–60 years with stage IIIB or IV HD received induction chemotherapy with 3 × (COPP + ABVD). Patients achieving CR were eligible for randomisation to either 20 Gy radiotherapy to initially involved fields (RT-arm) or to an additional 1 × (COPP + ABVD) (CT-arm). Patients with nodal PR were allocated to more intense radiotherapy (IRTarm: 20 Gy IF, 40 Gy to persisting tumor). Four patients with persisting organ involvement after induction received salvage chemotherapy. Of 288 patients, 171 (59%) achieved CR after induction chemotherapy. Of these, 100 patients were successfully randomized to RT or CT. In the CT arm relapses were observed in 10 of 49 patients compared with 13 of 51 patients in the RT arm (p = n.s.). Fifty patients refused randomisation and for them a treatment was chosen, and 21 patients refused any further treatment. Of these 21 patients with no consolidation therapy, 9 relapsed, indicating an approximately 3-fold increased relapse risk compared with those receiving either of the consolidation therapies. No relapse was observed in initially involved lung or liver sites. Adverse prognostic factors for freedom from treatment failure and survival were low hemoglobin and large mediastinal mass at initial presentation. No statistically significant differences in treatment efficacy were detected between 20 Gy IF radiotherapy and 1 × (COPP + ABVD) chemotherapy following CR after six cycles of alternating chemotherapy in patients with advanced-stage HD. However, limited observations in a non-randomized cohort indicate that patients without consolidation treatment of CR after 6 cycles of chemotherapy may have an elevated risk for relapse.