OUTLINE: Autologous peripheral blood stem cells (PBSC) are harvested and activated with interleukin-2 (IL-2) and sargramostim (GM-CSF) on another protocol. Patients receive oral busulfan every 6 hours on days -6 to -3 for a total of 16 doses. IL-2 and GM-CSF-activated PBSC are reinfused on day 0. Beginning 4 hours after PBSC infusion, patients receive IL-2 IV continuously for 5 days followed by 2 days of rest for 4 weeks. In addition, GM-CSF is administered subcutaneously (SC) every Monday, Wednesday, and Friday for 4 weeks. Upon hematologic recovery, but no earlier than 2 weeks after IL-2 and GM-CSF, patients receive interferon alfa SC 3 times weekly until clear evidence of disease progression. Patients are followed every 6 months for 3 years and then annually thereafter.