Low Dose Chemotherapy Versus Best Supportive Care in Progressive Pediatric Malignancies

"Metronomic chemotherapy schedule : Alternating cycles of Cycle A and B (Each cycle includes 3 weeks of drug administration) with each drug rounded off to the nearest tablet/capsule size.~Cycle A~* Daily oral Thalidomide (at 3mg/kg)~* Daily oral Celecoxib (100 mg BID for patients \< 20 kg, 200 mg BID for patients 20-50 kg, and 400 mg BID for patients \> 50 kg)~* Daily oral Etoposide (50 mg/m2/d)~Cycle B~* Daily oral Thalidomide (at 3mg/kg)~* Daily oral Celecoxib (100 mg BID for patients \< 20 kg, 200 mg BID for patients 20-50 kg, and 400 mg BID for patients \> 50 kg)~* Daily oral Cyclophosphamide (2.5 mg/kg/d to a maximum of 100 mg/d) every 21 days"