Current Strategies and Future Directions in Classification and Treatment of Uterine Sarcomas

Uterine sarcomas comprise endometrial stroma tumors (EST) and uterine leiomyosarcomas (ULMS), with ESTs accounting for less than 2% and ULMS accounting for approximately 1% of uterine neoplasms. Recent classifications of ESTs denote as many as four categories: benign endometrial stromal nodule (ESN), low-grade endometrial stromal sarcomas (ESS), high-grade endometrial stromal sarcomas (HGESS), and undifferentiated uterine sarcomas (UUS). The designation UUS has been suggested to encompass undifferentiated endometrial sarcomas (UES) and undifferentiated uterine sarcomas of other tissue origins. The prognosis for ESS is good. Although a third of cases recur, the 5-year survival rate for Stage I disease can be as high as 98%. In contrast the prognosis for UES is poor, with a 5-year survival rate for Stage I disease at 57%. Few patients with UES survive two years. ULMS represents the most common single type of uterine sarcoma and is associated with a poor prognosis. Recurrence rates are estimated at 50-70% and the 5-year survival rate for Stage I approximates 51%. The authors present a review of these tumors from the vantage point of clinical work up and diagnosis, treatment options, and adjuvant therapy including hormonal therapy, radiation therapy, and chemotherapy. Included are accounts of pertinent phase II and III clinical trials. The article concludes with commentary on future treatment directions for these rare tumors.