Clinical presentation, treatment, and outcome of alveolar soft part sarcoma in children, adolescents, and young adults.

PURPOSE

Alveolar soft part sarcoma is a rare soft tissue neoplasm that can affect children and adolescents. There are few reported series of these patients in the literature. To define the clinical presentation, treatment, and outcome of young people with this rare sarcoma, we reviewed our clinical experience.

METHODS

After institutional review board approval, we examined the records of all patients younger than 25 years old who received treatment at our institution for alveolar soft part sarcoma in the past 30 years. Demographics, tumor sizes, sites and extent of disease, treatments used, progression-free survival, and overall follow-up were evaluated.

RESULTS

Each of the 20 patients presented with a mass. Primary disease sites were thigh (n = 8), trunk (n = 6), retroperitoneum (n = 2), and scalp, neck, forearm, and calf (n = 1 each). Metastatic sites included lymph nodes, lung, and brain. Four patients presented to us with incomplete excision of the primary, and 1 had undergone embolization of what was thought to be a vascular malformation. Although wide local excision provided the best chance for a patient to remain free of disease, 14 (70%) of 20 patients exhibited metastases either at presentation or later. Thirty-one metastasectomies were performed. Chemotherapy was used in 11 patients; radiation was used in 8. Median overall follow-up was 36 months; median progression-free follow-up was 12.5 months. Younger patients tended to have Intergroup Rhabdomyosarcoma Study group I disease. Tumors smaller than 5 cm were associated with longer progression-free survival.

CONCLUSIONS

Achievement of complete microscopic resection is critical in localized alveolar soft part sarcoma, but incomplete excision and misdiagnosis are often encountered. Despite the occurrence of metastases in 70% of patients, 5-year overall survival was 83%. We found an association between smaller tumor size and longer time to progression. We were not able to demonstrate any benefit from chemotherapy or radiation. Metastasectomies have been performed in multiple long-term survivors.