Treatment of Uterine Sarcoma in Low-Grade Uterine Leiomyosarcoma, Hormone Receptor Positive, Metastatic

This protocol addresses a distinct subgroup of uterine leiomyosarcoma (uLMS): low-grade, hormone receptor-positive, metastatic disease with no evidence of transformation to high-grade LMS.

Low-grade uLMS represents a small, biologically separate population — often overlapping with tumors initially classified as smooth muscle tumors of uncertain malignant potential (STUMP). These tumors follow an indolent course with a lower recurrence risk than the more common high-grade uLMS variant, and hormone receptor positivity opens a specific therapeutic avenue.

High-grade and low-grade uLMS require different management. The low-grade, hormone receptor-positive subgroup can respond to endocrine-based approaches, making it important to confirm the absence of high-grade transformation before treatment selection.

For progressive disease in this setting, current evidence-based guidance recommends first-line endocrine therapy — the specific agent depends on menopausal status.