Double-alkylator non-total-body irradiation regimen with autologous hematopoietic stem-cell transplantation in pediatric solid tumors.
OBJECTIVE
To determine the maximum-tolerated dose (MTD) of cyclophosphamide (CTX) when administered with fixed doses of carboplatin, etoposide, and melphalan (CEM) followed by autologous hematopoietic stem-cell transplantation (HSCT) in children with recurrent or high-risk solid tumors as a consolidation chemotherapy, and to make preliminary observations on efficacy.


METHODS
Twenty-seven patients with solid tumors between the ages of 2 and 21 years were enrolled. Twenty of 27 had recurrent disease, whereas seven were treated in first remission. Nine were treated with melphalan 50 mg/m2/d for 4 days, carboplatin 300 mg/m2/d for 4 days as a continuous infusion (CI), and etoposide 200 mg/m2/d for 4 days as a CI (level I). CTX 750 mg/m2/d for 4 days was added to this regimen for the next 18 patients (level II). Seven of nine patients at level I and four of 18 at level II received bone marrow (BM) only, while two of nine at level I and 14 of 18 at level II received BM plus peripheral-blood stem cells (PBSC).


RESULTS
The median time to reach an absolute neutrophil count (ANC) greater than 500/microl was 12.5 and 10 days for patients who received BM only and BM plus PBSC, respectively. Three cases of grade 3 mucositis, one Candida sepsis, and two transient hypoxemias were the main nonfatal toxicities. No toxic mortality was observed among level I patients. Three of 18 (16%) level II patients, all in second CR, died of transplant-related complications. Median follow-up is 29 months. Nine died of progressive disease (one second malignancy), six relapsed and are alive with disease, and nine are in continuous CR. Among the 15 PNET/Ewing's sarcoma patients, seven are in continuous CR (three of nine in second CR/VGPR, four of six in first CR/VGPR).


CONCLUSIONS
The addition of CTX 3 g/m2 to CEM followed by autologous HSCT as a consolidation therapy resulted in 16% toxic mortality in children with recurrent or high-risk solid tumors. Further CTX dose escalation was aborted. No common nonhematologic toxicity was identified. The event-free survival (EFS) of 66% +/- 19% at 3 years for patients with metastatic PNET/Ewing's sarcoma in first remission is encouraging. However, this is based on only six patients. Both level I and II need further exploration in high-risk pediatric solid tumors in first remission.
Ozkaynak
M F
MF
Department of Pediatrics, New York Medical College, Valhalla 10595, USA. mehme1_02Kayaak@nymc.edu
Matthay
K
K
Cairo
M
M
Harris
R E
RE
Feig
S
S
Reynolds
C P
CP
Buckley
J
J
Villablanca
J G
JG
Seeger
R C
RC
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016026:Bone Marrow Transplantation; D016190:Carboplatin / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D003520:Cyclophosphamide / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D005047:Etoposide / Q000008:administration & dosage; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008297:Male; D008558:Melphalan / Q000008:administration & dosage; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D009364:Neoplasm Recurrence, Local / Q000628:therapy*; D016019:Survival Analysis; D014182:Transplantation, Autologous
D005047:Etoposide; D003520:Cyclophosphamide; D016190:Carboplatin; D008558:Melphalan