Low-grade endometrial stromal sarcoma: A Turkish uterine sarcoma group study analyzing prognostic factors and disease outcomes

Objective: To investigate factors associated with refractory disease, recurrence, or death as well as disease-free survival (DFS) and overall survival (OS) in low-grade endometrial sarcoma (LGESS). Methods: A multi-institutional, retrospective study was conducted in a total of 124 patients, who received a curative-intent surgery. The exclusion criteria were as follows: i) history of any other invasive disease; ii) neoadjuvant therapy; iii) fertility sparing surgery; iv) a different diagnosis after review of the slides. Results: All patients underwent hysterectomy, 96% had bilateral salpingo-oophorectomy, and 65% had lymphadenectomy. Twelve (14.8%) of 81 patients undergoing lymphadenectomy had lymph node (LN) metastasis. Of those, 8 (9.8%) had pelvic LN metastasis whereas 4 (5.6%) had isolated paraaortic LN metastasis. Six of 8 (75%) patients with positive pelvic LNs had concurrent paraaortic LN metastasis. Among 124 patients, 3 patients (2.4%) had refractory disease following primary therapy. During a median follow-up of 45.5 months, 27 (22.3%) of 121 patients who achieved complete remission after primary therapy developed recurrence, and 10 patients (8.1%) died of disease. The 3-year DFS and OS were 76.9% and 93.8%, respectively. Stage was the sole independent prognostic factor in the whole cohort. When analyzing factors within subgroups of stage I and stage ≥II, there was no significant prognostic factor for stage I; however, lymphadenectomy and adjuvant chemotherapy were significantly associated with disease outcomes for stage ≥II. While lymphadenectomy was related with improved DFS, chemotherapy was associated with poor DFS and OS. Conclusion: The risk of LN metastasis at pelvic as well as paraaortic lymphatic basins is not negligible to omit lymphadenectomy in stage ≥II LGESS. Moreover, lymphadenectomy provides significant DFS advantage in patients with extrauterine disease.