Long-Term Clinical Outcome of Women with Stage I-II Endometrial Adenocarcinoma after Adjuvant Intravaginal High-Dose-Rate Brachytherapy Alone

Abstract

Vaginal cuff brachytherapy is proven to be an effective and well tolerated adjuvant radiation treatment modality after hysterectomy in women with early stage endometrial carcinoma. However, there remains paucity of data in regards to long-term clinical outcome endpoints. In this IRB-approved retrospective study, 141 women with 2009 FIGO stage I-II endometrial adenocarcinoma were identified. All patients underwent hysterectomy followed by adjuvant intravaginal HDR brachytherapy. Various prognostic factors were analyzed using Cox proportional hazards regression. All patients underwent hysterectomy between 1990 and 2010 with at least one year followup after hysterectomy. Median followup was 48 months (range 13-245). Median age at diagnosis for the study cohort was 62 years (range of 39 to 91). Ninety-six patients (68.1%), 38 patients (27%), and 7 patients (5%) had stages IA, IB, and II endometrial adenocarcinoma, respectively. One hundred twenty-six patients (89.4%) had endometrioid carcinoma. The median number of lymph nodes sampled was 10 (range of 5-68). Peritoneal cytology was negative for malignant cells in all patients. All patients received adjuvant high-dose-rate vaginal brachytherapy through single channel vaginal cylinder. Median brachytherapy surface dose was 37.5 Gy in 5 fractions to the upper 3-4 cm of the vagina. Thirteen patients (9.2%) had adjuvant platinum-based chemotherapy. None of the patients reported more than grade 1 vaginal toxicity according to common toxicities criteria version 3.0. Only 6 patients (4.3%) were diagnosed with tumor recurrence including only one patient with an isolated vaginal recurrence. Five-year relapse-free, disease-specific, and overall survival rates were 93.2%, 96.3% and 89%, respectively. Due to small number of recurrences and based on exploratory analysis, there were no significant predictors of relapse-free or disease-specific survival. As expected, age as a continuous variable was the only variable that was a significant predictor of overall survival (p<0.001). Our results suggest that vaginal cuff brachytherapy alone provides excellent long-term control in patients with early stage endometrial carcinoma after surgical staging. The treatment is very well tolerated with minimal patient-reported side effects.