Conclusions from clinical trials of the Southwest Oncology Group

Mature data from four clinical trials conducted by the Southwest Oncology Group from 1971 to 1978 for patients with all stages of Hodgkin's disease (HD) are reviewed in this paper. In the RAC #1 trial of stage I and II HD we demonstrated that involved-field radiotherapy plus six courses of MOPP chemotherapy improved relapse-free survival compared to standard radiotherapy alone (P = 0.12), especially in patients with B symptoms (P less than 0.03) or mediastinal disease (P = 0.08). However, at present, there is no significant difference in overall survival. In the CAR #1 study for patients with pathologic stage IIB, IIIA, and IIIB HD, we demonstrated that three or four courses of MOPP before radiotherapy produced a 90% complete remission (CR) rate, with 70% of the patients remaining free of disease at 5 years. In the CAR #2 study for patients with pathologic stage IIIA or IIIB disease, we demonstrated that chemotherapy alone (MOPP-bleomycin) was as effective as combined modality treatment (MOPP-bleomycin plus radiotherapy) in terms of CR rate (85% versus 89%, respectively), relapse-free survival, and survival. For advanced stages of HD we added doxorubicin to our MOPP-bleomycin schedule and demonstrated that MOP-BAP produced a 77% CR rate compared to 67% for MOPP-bleomycin (P = 0.10). Moreover, MOP-BAP produced consistently superior CR rates and survival in patients with more prognostically favorable presentations of HD. Our new ongoing study (MOPP #6) incorporates many of the concepts derived from these earlier clinical investigations.