OUTLINE: This is a randomized study. Patients are randomized to one of two treatment arms. Arm I (ABVD): Patients receive doxorubicin IV, bleomycin IV, vinblastine IV, and dacarbazine IV on days 1 and 15. Courses repeat every 4 weeks. Arm II (ChlVPP/PABLOE): Patients receive oral chlorambucil, procarbazine, and prednisolone on days 1-14; vinblastine IV on days 1 and 8; doxorubicin IV on day 29; vincristine IV and bleomycin IV on days 29 and 36; oral etoposide on days 29-31; and oral prednisolone again on days 29-38. Courses repeat every 7 weeks. OR (Hybrid - ChlVPP/EVA): Patients receive vincristine IV on day 1; oral etoposide on days 1-5; oral chlorambucil, procarbazine, and prednisolone on days 1-7; and doxorubicin IV and vinblastine IV on day 8. Courses repeat every 4 weeks. Patients in both arms receive up to 6-8 courses of treatment. Radiotherapy may be given to sites of previous bulk disease for patients in complete remission or uncertain remission. Patients who achieve partial remission may receive radiotherapy to residual disease sites. Patients who fail to respond, or have disease progression, may receive induction therapy followed by high-dose consolidation therapy. Patients are followed every 3 months for 2 years, every 6 months for 5 years, and then annually for 5 years.