Refining surveillance in Myxoid liposarcoma: long-term recurrence patterns and functional outcomes after surgery ± radiotherapy in 186 patients.

Purpose To assess oncologic, functional outcomes, and recurrence patterns in a large cohort of prospectively collected patients with localized extremity/trunk myxoid liposarcoma with long-term follow-up.Methods Analysis of 186 patients (1992-2025) treated with surgery ± perioperative radiotherapy. Data were drawn from prospective institutional registries with central pathology/radiology review.Outcomes wound complications, late toxicity, functional scores, overall survival (OS), cancer-specific survival (CSS), and local (LR) and distant metastatic recurrence (DM).Results Median age was 44.5 years; median follow-up 77 months. All had surgery; 86.6 % received radiotherapy (73.7 % preoperatively). Wound complications occurred in 33.3 %. Late ≥ Grade 2 toxicities: skin (7.5 %), subcutaneous fibrosis (14.5 %), joint stiffness (2.2 %), edema (9.1 %). Functional scores at last follow-up: median TESS: 97 (mean 91.3), MSTS-87: 35 (mean 33.1), MSTS-93: 100 (mean 94.7). LR: 3 cases (1.6 %, 5-year cumulative incidence: 1.4 %). DM: 31 patients (16.7 %), involving 40 sites (42.5 % soft tissue, 22.5 % lung, 17.5 % bone, 7.5 % liver, 5 % lymph nodes). Cumulative incidence of DM: 1-year 0.6 %, 5-year 10.8 %, 10-year 23.4 %. CSS was 100 %, 96.4 %, and 80 % at 1, 5, and 10 years, respectively. OS was 98.8 %, 92 %, and 74.2 % at the same time points.Conclusions Local control was high, and long-term function were favorable. Distant recurrences were more frequent, occurred at a constant rate beyond 5 years, without plateau, often involved extra-pulmonary sites, and drove late cancer-related mortality. These findings support the consideration of continued annual follow-up through at least 10 years, with imaging of pulmonary and extra-pulmonary sites to adequately capture the full spectrum of metastatic risk.