Multi-institutional Analysis of Vaginal Brachytherapy Alone for Women With Stage II Endometrial Carcinoma

Purpose: To investigate the survival endpoints in women with International Federation of Gynecology and Obstetrics (FIGO) stage II endometrial cancer who received adjuvant vaginal brachytherapy (VBT) alone using multi-institutional pooled data. Methods and Materials: We performed a multi-institutional analysis of surgically staged patients with FIGO stage II endometrioid-type endometrial cancer treated with VBT alone. Patient, tumor, and treatment characteristics were collected and analyzed. Univariable and multivariable frailty survival models were performed to assess clinicopathologic risk factors for recurrence and death. Results: One hundred six patients were included (92 VBT alone and 14 VBT with chemotherapy) with median follow-up of 39.0 months. Pelvic node dissection was performed in 89.6% of patients. One hundred four patients (98.1%) and 2 patients (1.9%) had microscopic and macroscopic cervical stromal invasion, respectively. Grade 1 or 2 disease occurred in 88.6% of patients. For patients treated with VBT without chemotherapy, the 5-year estimates of vaginal failure, pelvic nodal failure, and distant metastases were 2.6%, 4.2%, and 7.2%, respectively. Five-year progression-free survival and overall survival were 74.0% and 76.2%, respectively. On univariable and multivariable models for progression-free survival, increasing age and lack of pelvic node resection were hazardous (P < .05). Conclusions: Vaginal and pelvic failure rates were low in this selected population of stage II patients receiving adjuvant VBT without external beam radiation therapy. It is reasonable to consider adjuvant VBT alone in selected patients with grade 1 or 2 disease and microscopic cervical stromal invasion who underwent pelvic lymphadenectomy.