Management of Soft Tissue and Visceral Leiomyosarcomas.
IMPORTANCE: Leiomyosarcoma is a rare and heterogeneous malignant mesenchymal neoplasm associated with substantial morbidity and mortality. Given recent advances in biologic understanding and the complexity of leiomyosarcoma, a consensus-driven approach is needed to harmonize management and address remaining clinical and research gaps. OBJECTIVE: To provide an evidence-based synthesis of current diagnostic and therapeutic approaches for leiomyosarcoma by an international panel of physicians, researchers, and patient advocates, focusing on site-specific management, systemic therapy strategies, and key areas of clinical uncertainty, while identifying unmet needs and research priorities. EVIDENCE REVIEW: This review is based on a comprehensive evaluation of the literature, including clinical trials, observational studies, and international consensus guidelines. Sources were identified through MEDLINE (via PubMed) and Embase database searches and reference screening, then supplemented by multidisciplinary expert consensus. Emphasis was placed on studies informing diagnosis, surgical management, radiotherapy, and systemic therapy in leiomyosarcoma. FINDINGS: The rarity and heterogeneity of leiomyosarcoma poses substantial challenges in its management. In localized disease, complete surgical resection remains the cornerstone of treatment, with evidence supporting the use of site-specific perioperative treatment strategies. Prospective data supporting neoadjuvant or adjuvant chemotherapy are lacking, and the role of radiotherapy differs across anatomic disease sites and institutions. In advanced disease, multiple systemic therapies demonstrate activity, including anthracycline-based and gemcitabine-based combinations, trabectedin, and tyrosine kinase inhibitors, although optimal sequencing after first-line therapy remains undefined. Emerging data suggest potential benefit from treatment continuation strategies and selected use of local therapies in oligometastatic settings. Molecular heterogeneity is increasingly recognized but has not yet translated into routine clinical implementation, and integration of molecular profiling into diagnostic pathways for predictive and therapeutic insights remains an unmet need. CONCLUSIONS AND RELEVANCE: This international consensus addresses the diagnosis and management of leiomyosarcoma. Management requires a multidisciplinary, site-specific approach informed by limited but evolving evidence. Key uncertainties persist, particularly regarding perioperative therapy, optimal sequencing and combination of systemic treatments, and integration of molecular data. Continued international collaboration and leiomyosarcoma-specific clinical trials are needed to refine treatment strategies and improve patient outcomes.