THE CLINICAL COURSE OF PATIENTS TREATED FOR BUTTOCK SARCOMA

Heller B, Gibbs JF, Skenderis B, Kraybill WG. (Roswell Park Cancer Institute, Buffalo NY 14263)

Background: Buttock soft tissue sarcomas (BSTS) present interesting management problems due to their location. The literature offers few clinical studies elucidating the clinical course of treated buttock sarcomas. The purpose of this study was to determine the characteristics of presentation and clinical course of patients with BSTS.

Methods: Thirty patients treated for BSTS at Roswell Park Cancer Institute (RPCI) were identified by a retrospective chart review from 1977 to 1998. Presentation and clinical course, patterns of recurrence, overall survival, and disease free survival were determined. Prognostic variables, including grade, size, histology, stage of disease and their effects on survival were assessed.

Results: Thirty patients (men 19, women 11) with a median age 58 years (21-90 yrs) were treated for BSTS. Twenty patients (67%) presented with local primary disease, 4 (13%) with local recurrence, and 6 (20%) with primary tumor and distant metastases. The time from initial symptom to definitive treatment was four months. Malignant fibrous histiocytoma (27%) and liposarcoma (23%) occurred most frequently. Fifty-seven percent of patients had tumors greater than 10 cm. Fifty-three percent of tumors were high grade. Surgical treatment consisted of radical buttectomy (n=28) or hemipelvectomy (n=2). The five- year overall survival from initial diagnosis was 62%. The five-year survival after referral to RPCI for all local primaries was 47%, surgically resectable local primaries 52%, and locally recurrent tumors 50%. Patients presenting with distant metastases had a one-year survival rate of 17%. The 5-year disease free survival for resected local primary tumors was 48%. The 5-year local control rate for primary localized tumors was 76%. The mean time to local recurrence for resected local primaries was 98 months. The only prognostic variables identified for increased survival were tumor histology of liposarcoma, complete surgical resection and previous excisional or attempt at excisional biopsy.

Conclusions: Data presented support aggressive surgical management of BSTS to render patients free of disease. The most important prognostic and therapeutic factor for survival appears to be complete surgical excision.