Soft tissue sarcomas of the buttock: A systematic review and meta-analysis

Soft tissue sarcomas of the buttock (BSTS) are historically associated with a poor prognosis. The literature includes retrospective studies with small sample size. It is difficult to estimate the rate of local recurrence (LR), distant metastasis (DM) and overall survival (OS). A systematic review and meta-analysis was deployed to summarize the available information on BSTS patients that underwent surgical treatment.

The PubMed, EMBASE, Scopus and Google Scholar databases were reviewed for eligible studies following PRISMA guidelines.

(1) primary BSTS confirmed by pathological biopsy (2) indication for surgical treatment (3) reporting either the rate of LR, DM, or OS at 5-year (4) articles published up to December 2021 (5) english language. The Methodological Index for Non-Randomized Studies (MINORS) was applied for the quality appraisal.

Six eligible studies with 216 BSTS patients were identified. Most patients underwent surgical resection, associated with radiation therapy. The most represented histological types were liposarcoma (n = 43, 19,9%), rhabdomyosarcoma (n = 27, 12.5%), and undifferentiated pleomorphic sarcoma (n = 23, 10.6%). High-grade tumor rates ranged from 37% to 88.2%, marginal resection rates from 20.3% to 50%, LR rates from 0% to 62.5%, DM rates from 37.5% to 62.5%. The pooled 5-year OS from 1941 to 2002 was 41% (IC95%: 33%-49%). The average MINORS score was 9.3 (range: 6 to 11).

Surgical resection of BSTS had on average dissatisfactory outcomes, and the 5-year overall survival was poor, with high rates of local recurrence and distant metastasis. An effort to collect new data with a higher level of evidence is warranted.