The importance of adjuvant chemotherapy and pelvic radiotherapy in high-risk early stage endometrial carcinoma.

Objective: To determine the impact of a policy change in which women with high-risk early stage endometrioid endometrial cancer (EEC) received adjuvant chemoradiotherapy.

Methods: This is a population-based retrospective cohort study of British Columbia Cancer Registry patients diagnosed from 2008 to 2012 with high-risk early stage EEC, who received adjuvant chemoradiotherapy after primary surgery. High-risk early stage was defined as the presence of two or more high-risk uterine factors: grade 3 tumor, more than 50% myometrial invasion, and/or cervical stromal involvement. Adjuvant therapy consisted of 3 or 4 cycles of carboplatin and paclitaxel chemotherapy, followed by pelvic radiotherapy. Sites and rate of recurrence were compared to a historical cohort diagnosed from 2005 to 2008 in which none of the patients received adjuvant chemoradiotherapy. Five-year progression-free and overall survival rates were calculated.

Results: The study includes 55 patients. All patients except for 2 received at least 3 cycles of chemotherapy. All patients received pelvic radiotherapy except for 2 who received brachytherapy only. Median follow-up was 27 months (7-56 months). Four patients (7.3%) recurred, including three with distant recurrence only and one with both a pelvic and paraaortic nodal recurrence. The historical cohort had a 29.4% recurrence rate, and therefore the hazard ratio for recurrence was 0.27 (95% CI 0.02-4.11). Five-year progression-free and overall survival rates were 88.6% and 97.3%, respectively.

Conclusion: Patients with high-risk early stage endometrial carcinoma treated with adjuvant chemoradiotherapy have a low rate of recurrence compared to those not receiving such therapy.