OUTLINE: This is a dose de-escalation study. Patients receive etoposide IV continuously on days 1-3; cyclophosphamide IV on day 8; donor lymphocyte infusion IV on day 10; and filgrastim (G-CSF) subcutaneously or IV beginning on day 10 and continuing until blood counts recover. Cohorts of 3-6 patients receive six de-escalating levels of chemotherapy until the minimum amount of chemotherapy in combination with donor lymphocyte infusion required to obtain a rate of 30-60% graft versus host disease (GVHD) is determined. The target dose level is defined as the level at which 2 of 6 patients develop GVHD, and the next lower dose level has no more than 1 patient experiencing GVHD. Patients are followed every 3 months for the first year, every 6 months for the second year, and yearly thereafter.