Impact of Body Mass Index on Tumor Recurrence and Survival for Patients with Early Stage Endometrial Carcinoma after Adjuvant HDR Vaginal Cuff Brachytherapy

Abstract

Increasing body mass index (BMI) is associated with increased prevalence of endometrial carcinoma (EC). We sought to investigate the significance of BMI as a prognostic factor for tumor recurrence and survival in women with early stage endometrial carcinoma who were treated with adjuvant HDR vaginal cuff brachytherapy. In our prospectively-maintained database of patients with endometrial cancer, we identified 141 patients who underwent surgical staging between 1990 and 2010 for FIGO stage I-II and received adjuvant high-dose-rate vaginal cuff brachytherapy. Their medical records were retrospectively reviewed in this IRB-approved study. Height and weight data were available at time of hysterectomy from which BMI was calculated (<30, ≥30 - <38 and ≥38). Following a univariate analysis, multivariable modeling was done using Cox regression analysis. Median followup was 48 months (range 13-245), median age was 62 years (range 39-91) and median BMI is 33.7 (range 19.7 - 63.6). There were 126 patients (89.4%) with endometrioid histology, 96 patients (68%) with stage IA, 38 patients 27% with stage IB and 7 (5%) with stage II. Median brachytherapy dose was 37.5 Gy to the surface of a vaginal cylinder in 5 fractions. Only 13 patients (9.2%) received adjuvant chemotherapy. There were only 6 patients with recurrences including only one patient with isolated vaginal cuff recurrence. Due to small number of events and based on exploratory analysis, body mass index (as a continuous variable or categorical) was not a significant predictor of recurrence-free, or disease-specific survival. BMI ≥38 and older age were the only independent predictor of OS (p=0.02 and <0.001, respectively). Five-year recurrence-free, disease-specific and overall survival for the study cohort was 93.2%, 96.3% and 89%, respectively. In our study, vaginal cuff control was excellent with vaginal brachytherapy. Body mass index was not a predictor of tumor recurrence or disease-specific survival in patients with early stage endometrial carcinoma who underwent surgical staging followed by adjuvant vaginal cuff HDR brachytherapy.