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.