Evolving trends in the management of high-intermediate risk endometrial cancer in the United States.

Objective: Gynecologic oncology group protocol 249 (GOG 249) is the contemporary US study that aimed to define the standard of care adjuvant therapy for patients with high-intermediate risk (HIR) endometrial cancer; patients were randomized to pelvic radiation therapy (RT) or vaginal brachytherapy (VBT) with chemotherapy (VBT-C). The preliminary results of GOG 249 were recently presented, yet the management of patients represented in this trial remains controversial. We set out to review US patterns of care for patients meeting eligibility criteria for GOG 249.

Methods: The National Cancer Database (NCDB) was used to identify patients meeting GOG 249 eligibility criteria between 2010 and 2015. The Man-Kendall trend test was used to assess for significant trends over time.

Results: We identified 23,015 patients that met study inclusion criteria. Between 2010 and 2015, there was a decline in the use of pelvic RT from 9.8% to 7.5%, although not meeting statistical significance (p = 0.136), and an increase in the use of VBT-C from 4.6% to 7.7% (p = 0.017). Most patients did not receive treatment per either arm of GOG 249, with observation being the most common approach throughout this era, although the percentage of patients observed decreased from 58.1% to 45.8% between 2010 and 2015 (p = 0.003). Further, 21.5% of patients received VBT alone in 2010, increasing to 30.3% by 2015 (p = 0.003).

Conclusions: National practice trends in HIR endometrial cancer reveal that a large number of patients are observed in lieu of receiving adjuvant therapy. Further, the utilization of pelvic RT has declined below utilization of VBT-C, despite a lack of data supporting either improved disease outcomes or toxicity with this experimental regimen on GOG 249.