RATIONALE: Drugs used in chemotherapy, such as irinotecan, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing.

PURPOSE: This phase II trial is studying how well irinotecan works in treating patients with newly diagnosed Ewing's sarcoma.

OBJECTIVES:

Primary

• Assess the responsiveness of single-agent irinotecan hydrochloride in a patient population with newly diagnosed high-risk Ewing's sarcoma.

OUTLINE: This is an open-label, multicenter study.

Patients receive irinotecan hydrochloride IV over 1 hour on day 1. Treatment repeats every 21 days for 2 courses. After completion of 2 courses of therapy, patients may receive additional treatment at the discretion of the treating physician.

After completion of study treatment, patients are followed periodically.

PROJECTED ACCRUAL: A total of 35 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed Ewing's tumor

  • Ewing's sarcoma or peripheral primitive neuroectodermal tumor of bone or soft tissue
  • High-risk disease (R3), defined as metastases at extrapulmonary/pleural sites

• Newly diagnosed disease

• Measurable primary and/or metastatic disease

  • At least one bidimensionally measurable lesion

• Concurrent enrollment on EURO-Ewing99 clinical trial required

PATIENT CHARACTERISTICS:

• No abnormal cardiac function, including any of the following:

  • Fractional shortening < 29%
  • Ejection fraction < 40%

• Glomerular filtration rate ≥ 60mL/min

• Not pregnant

• Negative pregnancy test

• Fertile patients must use effective contraception during and for 3 months after completion of study treatment

• No prior or current history of chronic diarrhea, bowel obstruction, sub obstruction, Crohn's disease, or ulcerative colitis

• No other medical, psychiatric, or social condition incompatible with the study treatment

PRIOR CONCURRENT THERAPY:

• No prior chemotherapy
• No more than 45 days since prior definitive biopsy