Pediatric alveolar soft part sarcoma seems to have a better outcome than its adult counterpart. In a series of 19 treated patients, one group reported a 5-year OS rate of 80%, a 91% OS rate for patients with localized disease, a 100% OS rate for patients with tumors 5 cm or smaller, and a 31% OS rate for patients with tumors larger than 5 cm. In another series of 33 patients, OS was 68% at 5 years from diagnosis and 53% at 10 years from diagnosis. Survival was better for smaller tumors (≤5 cm) and completely resected tumors.[Level of evidence: 3iiA]
The standard approach is complete resection of the primary lesion. If complete excision is not feasible, radiation therapy should be administered.
The value of adjuvant chemotherapy in completely resected alveolar soft part sarcoma remains unproven, particularly because patients with unresected or metastatic tumors failed to respond to chemotherapeutic agents frequently used to treat STSs. Alveolar soft part sarcoma is considered a chemoresistant tumor. There are sporadic reports of objective responses to interferon-alpha, bevacizumab, and sunitinib.[79,80,81,82]
Patients with alveolar soft part sarcoma may relapse several years after a prolonged period of apparent remission. Because these tumors are rare, all children with alveolar soft part sarcoma should be considered for prospective clinical trials.
Treatment options under clinical evaluation for alveolar soft part sarcoma
The following is an example of a national and/or institutional clinical trial that is currently being conducted. Information about ongoing clinical trials is available from the NCI Web site.
- NCT00942877 (Phase II Study of Cediranib in Patients With Alveolar Soft Part Sarcoma): This phase II study of cediranib in patients with alveolar soft part sarcoma is being conducted at the Clinical Center of the National Institutes of Health. Patients aged 18 years and older are eligible to participate.
Clear cell sarcoma of soft tissue
Clear cell sarcoma (formerly and inappropriately called malignant melanoma of soft parts), also called clear cell sarcoma of tendons and aponeuroses, is somewhat similar to cutaneous malignant melanoma but is cytogenetically distinct; most cases have a t(12;22)(q13;q12) translocation that has not been reported in melanoma. In one series, clear cell sarcoma demonstrated a propensity to metastasize to regional lymph nodes (12%–43%).
Patients who have small, localized tumors with low mitotic rate and intermediate histologic grade fare best.
The primary treatment for clear cell sarcoma is complete surgical resection, with the addition of radiation therapy for uncertain or involved margins. Chemotherapy is rarely effective.
Desmoplastic small round cell tumor
Desmoplastic small round cell tumor is a primitive sarcoma that most frequently involves the abdomen, pelvis, or tissues around the testes.[88,89,90] The tumor occurs more commonly in males and invades locally but may spread to the lungs and elsewhere.