Soft tissue sarcoma as a second malignant neoplasm in the pediatric age group.

BACKGROUND: Survivors of childhood malignancies have an increased risk of developing second malignant neoplasms (SMN) due to their prior treatment and/or genetic susceptibility. A small proportion of SMNs are soft tissue sarcomas (STS), whose prognosis is generally thought to be poor, though publications on such patients' treatment and outcome is limited. METHODS: The authors analyzed 25 patients who were registered for the Italian Cooperative Group protocols for pediatric STS from 1979 to 2000. The primary tumor was STS in five patients; Hodgkin disease in five patients; leukemia in four patients; retinoblastoma, neuroblastoma, and Wilms tumor in two patients each; and other tumor types in five patients. SMNs occurred after a median of 8 years (range, 1.9-15.0 years) and included rhabdomyosarcoma (RMS) in 4 patients, malignant peripheral nerve sheath tumor in 4 patients, extraosseous Ewing family tumor (EFT) in 4 patients, leiomyosarcoma in 3 patients, fibrosarcoma in 2 patients, synovial sarcoma in 2 patients, and other tumor types in 6 patients. Treatment generally was administered according to the guidelines for primary STS. RESULTS: Seven non-RMS patients with STS underwent surgery alone, whereas 18 patients received chemotherapy and 8 patients received radiotherapy. Retreatment was feasible with acceptable toxicity. Fifteen patients were alive in complete remission of their SMN at the time of last follow-up. Responses to chemotherapy and survival were satisfactory for patients with tumors such as RMS and EFT. Complete tumor resection was correlated with a favorable prognosis in patients with other types of STS and in patients with postirradiation sarcoma. Two patients developed a third malignancy. CONCLUSIONS: Although prior treatment may hinder the management of these patients, pediatric STS second malignancies can be cured using the same strategies used for de novo pediatric sarcomas. Long-term follow-up is mandatory given the risks of further malignancies and more severe, treatment-related side effects.