, according to results from a phase 3 trial.
The GOG-0249 study comprised 601 patients with high-intermediate– and high-risk early-stage endometrial carcinoma who were randomized in a 1:1 fashion to receive vaginal cuff brachytherapy plus paclitaxel and carboplatin or pelvic RT every 21 days for a total of three cycles.
Those in the brachytherapy group received treatment at both high and low-dosing rates. Paclitaxel was given at a dose of 175 mg/m2 infused over 3 hours, succeeded by carboplatin (area under the curve, 6) infused over 45 minutes. Pelvic RT was provided at a dose of 45 to 50.4 Gy over a period of 5-6 weeks.
“The primary objective was to determine if vaginal cuff brachytherapy and chemotherapy increases recurrence-free survival (RFS) compared with pelvic RT,” wrote Marcus E. Randall, MD, of the University of Kentucky, Lexington, and colleagues. The report is in the Journal of Clinical Oncology.
Additional outcomes measured were overall survival and acute toxicity.
After analysis, the researchers found that vaginal brachytherapy plus chemotherapy did not show superiority over pelvic RT in terms of 60-month RFS (hazard ratio, 0.92; 90% confidence limit, 0.69-1.23). Also, there was no significant difference for overall survival (HR, 1.04; 90% confidence limit, 0.71-1.52).
With respect to safety, acute adverse events were more common and severe in the vaginal brachytherapy plus chemotherapy group. However, “differences in late toxicity were minimal,” Dr. Randall and colleagues reported.
“Pelvic RT remains an appropriate treatment for high-risk early-stage endometrial carcinoma,” they wrote. “Novel combinations, dose intensification, and additional translational research represent potential paths forward.”
The study was supported by grant funding from the National Cancer Institute and the Memorial Sloan Kettering Cancer Center. The authors reported financial affiliations with AstraZeneca, Genentech, Genmab, Janssen, Johnson & Johnson, Tesaro, and several others.
SOURCE: Randall ME et al. J Clin Oncol. 2019 Apr 17. doi: 10.1200/JCO.18.01575.