OUTLINE: This is a randomized, double blind, placebo controlled, multicenter study. Patients are stratified by center. Patients are randomized to one of three treatment arms. Arm I: Patients receive 7 doses of recombinant human keratinocyte growth factor (rHuKGF). Arm II: Patients receive 4 doses of rHuKGF followed by 3 doses of placebo. Arm III: Patients receive 7 doses of placebo. Patients receive one of two conditioning regimens. Primary conditioning regimen: Patients receive rHuKGF or placebo daily on days -11, -10, -9, -5, 0, 1, and 2. Total body irradiation (TBI) is administered twice a day on days -8 to -5. Patients receive etoposide on day -4, cyclophosphamide IV over 1 hour on day -2, and peripheral blood stem cell transplantation (PBSCT) on day 0. Filgrastim (G-CSF) IV or SC is administered beginning on day 0 and continuing for 21 days or until blood counts recover. Secondary conditioning regimen: Patients receive rHuKGF or placebo daily on days -13, -12, -11, -7, 0, 1, and 2. TBI is administered twice a day on days -10 to -7. Patients receive ifosfamide IV over 1 hour followed by etoposide over 23 hours on days -6 to -2, then PBSCT on day 0. G-CSF IV or SC is administered beginning on day 0 for 21 days or until blood counts recover. Quality of life is assessed daily beginning on day -11 and continuing until day 28. Patients are followed at day 28 and then at day 60-100.