Uterine Leiomyosarcoma

Uterine leiomyosarcoma (uLMS) is a rare and aggressive gynecologic cancer of the uterus—a subtype of leiomyosarcoma, which is cancer that develops in any smooth muscle tissue. uLMS typically affects women during perimenopause between the ages of 45 and 60.

uLMS often presents similarly to benign uterine fibroids, which are common, affecting an estimated 70–80 percent of women. As a result, uterine masses are frequently presumed benign and monitored conservatively.

The similarity to fibroids can lead to missed opportunities in recognizing uLMS. Due to its aggressive behavior, uLMS generally has a poor prognosis, especially if diagnosed after metastasis has occurred.

uLMS is often discovered incidentally during surgeries intended to remove presumed benign uterine fibroids. For every 1,000 such surgeries, approximately one to five patients are later diagnosed with uLMS. This cancer grows and metastasizes quickly, with survival rates dropping significantly when detected at advanced stages.

The biological complexity and variability of uLMS make it difficult to identify effective therapeutic targets. The lack of preclinical model systems further compounds research challenges, and no FDA-approved uLMS-specific therapies exist today.

Due to its rapid progression, limited treatment options, and poor survival outcomes, uLMS presents a critical unmet need in women’s cancer research.