PRIOR CONCURRENT THERAPY: Biologic therapy: No prior bone marrow transplantation Chemotherapy: At least 4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosoureas) and recovered Endocrine therapy: Not specified Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy and recovered No prior radiotherapy to more than 25% of bone marrow Surgery: See Disease Characteristics Recovered from major surgery