Phase II trial of vaginal cuff brachytherapy followed by dose-dense chemotherapy in early stage endometrial cancer patients with enriched, high-intermediate risk factors for recurrence

Objective: To determine the feasibility of vaginal cuff brachytherapy (VCB) followed by 3 cycles of dose dense paclitaxel and carboplatin chemotherapy (ddTC) in enriched, high-intermediate risk (H-IR) patients with early stage endometrial cancer following hysterectomy.

Methods: A phase II trial of early stage endometrial cancer patients treated with VCB (2100 cGy) followed by three cycles of carboplatin (AUC 6) and dose dense paclitaxel (80 mg/m²) weekly within 12-weeks of surgery was conducted. The primary endpoint was the proportion of patients completing both VCB and ddTC. Secondary outcomes include short and long-term toxicities, recurrence rate and sites, and progression free survival. Toxicity assessments were patient reported as well as those resulting in delays or dose modifications.

Results: A total of 32 evaluable patients with median age of 64.5 years were included. Most patients were endometrioid histology (18/32, 56.3%) and fully staged (21/32, 65.6%) to stage Ib (18/32, 56.3%). In total, 27/32 (84.4%) patients completed treatment per protocol. Protocol non-completion included renal insufficiency, paclitaxel reaction, and treatment refusal. Median time to VCB completion was 11 days with all patients completing three fractions of VCB. Acute toxicities with VCB included grade 1 and 2 gastrointestinal, genitourinary and fatigue symptoms. Acute toxicities associated with ddTC included infusion reaction and neutropenia. Most reported long-term toxicities were grade 1 or 2 and resolved with time.

Conclusions: Treatment with VCB followed by three cycles of ddTC is well-tolerated with promising utility for treatment in enriched high-intermediate risk endometrial cancer patients. Recurrence-free and overall survival outcomes are not yet mature.