(OA21) Outcomes After Salvage Therapy for Recurrent Early Stage Endometrial Cancer

Abstract

We sought to analyze our institutional experience and oncologic outcomes for salvage treatment for recurrence of early stage endometrial cancer patients. We analyzed women of all ages diagnosed with FIGO stage I-II endometrial cancer of any grade between 2000-2016 at our institution. All women received hysterectomy. Leiomyosarcoma histology was excluded. Recurrences in the pelvis or vagina were considered locoregional (LRR). Overall survival (OS), disease free survival (DFS) and recurrence were assessed using Kaplan-Meier survival analysis. Univariate (UV) and multivariate (MV) Cox proportional hazards modeling was used to identify factors associated with survival and recurrence. 988 women were included. 73% had stage IA disease; 88% had endometrioid histology. 5% of women had adjuvant chemotherapy and 29% had adjuvant radiation (66% vaginal brachytherapy [VB] alone, 23% external beam radiation [EBRT] alone, and 11% EBRT + VB). At a median follow up of 4.8 years there were 101 (10.2%) failures (29 vaginal failures, 29 pelvic failures, and 43 distant failures). 17% of vaginal failures and 59% of pelvic failures had prior radiation. The median OS for patients without recurrence was 16.0 years vs. 5.2 years for those with recurrence, p<0.001. Of the 58 women with LRR, 28% had salvage surgery, 74% had salvage radiation (66% EBRT alone, 27% EBRT + VB, and 7% VB alone), and 35% had salvage chemotherapy. With a median follow up of 1.5 years after initial recurrence, 5/58 women had second LRR and 7/58 failed distantly. The median and 3 year DFS after initial recurrence for those without a second recurrence was 3.6 years and 51.2%, respectively, compared to 1.3 years and 8.3%, respectively, for those with a second recurrence (p=0.0064). On MV analysis, increasing age (Hazard Ratio [HR] 1.05, p=0.046) and pelvic site of initial recurrence (HR 2.6, p=0.034) were associated with worse DFS. When analyzing vaginal only recurrences, on MV analysis, salvage radiation was the sole treatment modality associated with improved DFS (HR 0.19, p=0.013). For women with early stage endometrial cancer rates of failure are low, but not insignificant. However, the majority of women with LRR were successfully salvaged with additional treatment. Salvage radiation appears to be the most important element of salvage therapy for vaginal recurrences.