High-grade soft tissue sarcomas of the buttock: a case series and surgical technique

Abstract

Abstract Objective Soft tissue sarcomas of the buttock (BSTS) are historically associated with a poor prognosis. The literature concerning BSTS includes outdated single-center retrospective case series, and case reports. We aimed to analyze the oncologic outcomes of high-grade BSTS according to current treatment modalities, and to present a detailed surgical technique of buttectomy,. Methods Consecutive patients diagnosed with BSTS from 2016 to 2021, were retrospectively evaluated for the rate of local control, distant metastases, overall survival (OS) and disease-free survival (DFS). Inclusion criteria: (1) high-grade STS confirmed by pathological biopsy, (2) tumors localized to the buttock, (3) surgical treatment, (4) age > 18 years. All patients underwent surgical resection. Chemotherapy and/or radiation therapy was administered according to a standardized protocol. Functional outcome was assessed with the Musculoskeletal Tumor Society score (MSTS 1993). Results Nine high-grade, G2/3 BSTS were included; mean age 60.1 years (range, 30–86), and mean follow-up 4,5 years (range, 1–7). There were 7 undifferentiated pleomorphic sarcoma, 1 fibrosarcoma, and 1 myxoid liposarcoma. Three patients were referred after whoops surgeries, 33% (3/9). Overall, the deep gluteal space was invaded in three out of nine patients, and the subcutaneous fat in another three out of nine patients; wide margins were achieved only in two patients. At the last follow-up, two patients developed distant metastasis and died, in one case with invasion of the deep gluteal space, and in another of the subcutaneous fat; 7/9 patients were alive and disease-free. The LR rate was 33% (2/6), the 5-year OS and DFS were 66% (5/7). The MSTS 1987 scores averaged 89.0 (range 76–100). Conclusion BSTS are still associated with high rates of whoops surgeries and local recurrence in agreement with previous evidence from 1948 to 2002. Buttectomy for high-grade BSTS provided acceptable oncological outcomes when performed by a trained team using a precise surgical technique, in association to a multimodal therapy.