Irinotecan, Temozolomide and Bevacizumab in Combination With Existing High Dose Alkylator Based Chemotherapy for Treatment of Newly Diagnosed Patients With Desmoplastic Small Round Cell Tumor

Inclusion Criteria: * Age greater than or equal to 1 year, less than 30 years * Newly diagnosed, previously untreated patients with histologically or molecularly confirmed DSRCT * Adequate hematologic function: * Absolute neutrophil count ≥ 1,000/mm3 * Platelet count ≥ 100,000/mytm3 * Adequate renal function: * Normal creatinine for age OR * Creatinine clearance or radioisotope GFR ≥ 70ml/min/1.73 m2 * Adequate hepatic function: * Total bilirubin ≤ 1.5 x the ULN for age * AST ≤ 2.5 x the ULN for age \[in the absence of hepatic involvement of tumor\] * Normal cardiac function * Shortening fraction greater than or equal to 28% by echocardiogram OR * Left ventricular ejection fraction (LVEF) greater than or equal to 50% on technetium-99m pertechnetate radionuclide cineangiography (MUGA) or echocardiogram * Hypertension must be well controlled on stable doses of medication for at least two weeks prior to enrollment. * Patients must consent to an indwelling central venous catheter. * Sexually active patients of reproductive potential must be willing to use an effective method of contraception. Exclusion Criteria: * Prior chemotherapy or radiotherapy * Pregnant or breastfeeding females * Patients with documented chronic non-healing wound, ulcer or bone fracture. * Incomplete healing from previous oncologic or other major surgery. * Surgical procedures: Patients who have undergone major surgery (including open biopsy, thoracotomy, organ resection, exploratory laparotomy, arterio…