Epithelioid sarcoma in children and adolescents: a report from the Italian Soft Tissue Sarcoma Committee

Epithelioid sarcoma (ES) is an uncommon malignant soft tissue tumor. To the authors' knowledge, little information is available to date concerning its clinical features and management in children and adolescents, particularly with regard to the recently described proximal-type variant. The current study concerns 30 patients age<18 years who were enrolled in the Italian Soft Tissue Sarcoma Committee protocols.

Histopathologic specimens, clinical data, and treatment modalities were reviewed for the current analysis. Nineteen patients had classic ES and 11 had proximal-type ES. Surgery was the mainstay of treatment; radiotherapy was given to six patients considered to be at risk of local disease recurrence due to incomplete resection, and chemotherapy was administered to eight patients.

With a median follow-up of 66 months, the 5-year event-free survival (EFS) and overall survival (OS) rates were 61.7% and 92.4%, respectively, but the OS rate dropped to 86.9% and 72.4%, respectively, at 10 years and 15 years. Local disease recurrence was the major cause of treatment failure. The most significant finding influencing both EFS and OS was tumor site, with a tumor location in the extremities predicting a favorable outcome. Initially unfavorable clinical findings and a worse outcome were associated with the proximal-type variant of ES. A response to chemotherapy was noted in three of the seven patients with measurable disease.

The current study confirms some typical features of ES (i.e., the peculiar superficial distal location [i.e., the hand, fingers], indolent growth, and a tendency to recur locally). The current study data do not clearly confirm the strong tendency for the lymph node involvement described in adult ES patients. Further studies are needed to better define the clinical behavior and biology of the proximal-type variant of ES.