COLLECTION AND USE OF PERIPHERAL-BLOOD STEM-CELLS IN YOUNG-CHILDREN WITH REFRACTORY SOLID TUMORS

Fifteen children 4 years of age or under (8-46 months), weight 7.8 to 17 kg, underwent 44 peripheral blood stem cell (PBSC) collections, Dia gnoses included PNET/medulloblastoma (five), neuroblastoma (five), and others (five), PBSCs were collected following G-CSF/GM-CSF or chemoth erapy plus G-CSF/GM-CSF mobilization. All PBSC collections were well t olerated, The average yield per collection was 6.80 x 10(8) mononuclea r cells/kg (1.1-30 x 10(8)/kg) or 57.60 x 10(6) CD34(+)/kg (1.37 to 48 0 x 10(6)/kg), Eight patients underwent stem cell transplantation foll owing myeloablative chemotherapy, Six of the eight children who receiv ed PBSC following myeloablative therapy also received autologous bone marrow (0.7 to 3.6 x 10(8) MNC/kg), One heavily pretreated patient exp erienced delayed hematologic reconstitution, while the remaining seven patients had a median ANC recovery to >0.5 x 10(3)/mu l by day +10 (9 -11 days) and platelets >50 x 10(3)/mu l by day +15 (12-17 days), Seve n patients received PBSCs following repetitive submyeloablative chemot herapy (ICE: ifosfamide 1.8 g/m(2)/day, etoposide 100 mg/m(2)/day x 5, carboplatin 400 mg/m(2)/day x 2) or other similar combination chemoth erapy, Median days to recover ANC greater than or equal to 1 x 10(3)/m u l and platelets greater than or equal to 100 x 10(3)/mu l in childre n receiving ICE + PBSCs were 10 and 14 days, respectively, compared wi th 16 and 22 days in children receiving ICE + G-CSF in historical cont rols, In conclusion, collection and use of PBSCs to support either mye loablative chemotherapy or multicycle submyeloablative chemotherapy is well tolerated and may enhance hematological recovery in young childr en and infants.