ASO Practice Guidelines Series: Multidisciplinary Management of Retroperitoneal Sarcomas.

Retroperitoneal sarcomas (RPS) represent a rare and biologically diverse group of malignancies, distinct from soft tissue sarcomas arising in other anatomic regions. Their deep-seated location, large size at presentation and proximity to critical structures contribute to diagnostic delays, treatment challenges, and variable oncologic outcomes, particularly when managed outside high-volume referral centers. Current international guidelines emphasize the importance of preoperative biopsy, review by a sarcoma pathologist, management in a referral center, multidisciplinary case discussion, consideration for clinical trials enrollment, and prospective database inclusion as standards of care. Given that the quality of the initial surgical resection-achieving complete macroscopic resection with margins tailored to the histologic type-remains the most important modifiable prognostic factor, adherence to international best practices in surgical and multimodal treatment is crucial to optimize patient outcomes. This article reviews contemporary management strategies for adult-type RPS, emphasizing the importance of multidisciplinary expertise.