Undifferentiated uterine sarcoma : experience of a single center.

Objectives: To investigate the clinicopathological characteristics and prognosis of patients with undifferentiated uterine sarcomas (UUS).

Methods: 29 patients with UUS who were treated at our institution between 2001 and 2020 were analyzed.

Results: The median age at diagnosis was 52 years (range: 26-70 years). The FIGO 2009 distribution by stage was as follows: stage I, 17 patients (58.6%); stage II, 5 patients (17.2%); stage III, 4 patients (13.8%); and stage IV, 3 patients (10.3%). For 28 patients who underwent surgical treatment, 27 patients (96.4%) underwent total/sub-radical/radical hysterectomy combined bilateral salpingo-oophorectomy, 17 (58.6%) pelvic lymphadenectomy, 7 (24.1%) para-aortic lymphadenectomy and 8 (28.6%) patients underwent omentectomy, as part of the initial surgical treatment. The median follow-up was 23.4 months (range: 4.5-200.2 months). 18 patients (62.1%) died during follow up, and 13 patients (72.2%, 13/18) died within 2 years after diagnosis. Median progression-free survival (mPFS) and overall survival (mOS) for the entire cohort were 15.5 and 27.4 months, respectively. 2-year and 5-year PFS were 40.3% and 26.9%. 2-year and 5-year OS were 54.0% and 36.5%. Stage-specific median PFS and OS were as follows: stage I-II-17.7 and 35.5 months, stage III-IV-6.0 and 6.7 months. Patients with recurrent UUS who underwent cytoreduction surgery associated with an improved overall survival (mOS: 52.9 vs. 17.9 months), but the difference was not statistically significant (P = 0.081).

Conclusions: UUS are a rare group of tumors with an aggressive behavior and poor outcomes. A majority rapidly develops distant metastases despite surgical resection.