470 Prognostic Factors and Impact of Adjuvant Therapy for Uterine Leiomyosarcoma

Background: The aim of this study was to investigate prognostic factors and impact of adjuvant therapy for uterine leiomyosarcoma (LMS). Methods: Using the ICD-9 and SNOMED codes, All cases with LMS were retrieved from medical registry (1983 through 2003). After excluding cases with initial surgery at outside hospital, missing chart and wrong pathologic diagnosis, 51 patients (41 stage I, 7 stage III and 3 stage IV) met the study criteria. Stratified analysis and Cox proportional hazards model were used to adjust confounding factors. Results: The median follow-up for survivors was 47 months. 5-year overall survival (OS) and relapse free survival rates were 74.5% and 66.7%, respectively. By stratified analysis, age (< = 50 vs >50 years), stage (I vs III & IV), tumor size (< = 11 vs >11 cm) and mitotic count (< = 14 vs >14 per 10 HPF), adjuvant chemotherapy (CT) (yes vs no) were identified as significant prognostic factors. Moreover, multivariate Cox regression analysis selected age >50 (P = 0.005), tumor size >11 cm (P = 0.003), stage III&IV (P = 0.006) and lack of CT (P = 0.031) as significantly associated with worse OS. Pelvic and/or aortic LN dissection was performed in 21 of 51 patients. No LN metastasis was noticed in this series. Conclusions: This is the first report to address the benefit of adjuvant CT for LMS in medical literature despite the limitation of its retrospective nature. Prospective multicenter trials are necessary to further clarify the role of multimodality treatment and optimal CT regimen for LMS.