Population-based treatment and outcomes of Stage I uterine serous carcinoma

• 3% recurrence rate after chemoradiotherapy for Stage IA USC with < 50% myometrial invasion.
• 30% recurrence rate after chemoradiotherapy for Stage IB USC underscores the need for alternate strategies.

ObjectiveUterine serous carcinoma (USC) is a rare type of endometrial cancer that often recurs in patients with Stage I disease. Our objective was to evaluate treatment and outcomes in Stage I USC in the context of a population-based study.MethodsThis was a population-based retrospective cohort study of all patients with Stage I USC in British Columbia, Canada from 2004 to 2012. The British Columbia Cancer Agency (BCCA) recommends three cycles of paclitaxel and carboplatin chemotherapy followed by pelvic radiotherapy for all women with Stage I USC and any myometrial invasion (Stage IA MI −). If no myometrial invasion (Stage IA MI −), no postoperative treatment is given. Patient and disease characteristics, surgery, adjuvant therapy, recurrence rates and sites, and 5-year disease-free survival rates were evaluated.ResultsOf the 127 patients with Stage I USC, 41 were Stage IA MI −, 56 Stage IA MI +, and 30 Stage IB. Median follow-up was 25 months (2–98 months). Five year disease-free survival rates were 80.7%, 74.4%, and 48.5% for Stages IA MI −, IA MI +, and IB, respectively, and recurrence rates according to BCCA guidelines were 10%, 2.9% and 30%, respectively. Of the 18 with recurrences, 13 had a distant component (72.2%). There were no pelvic recurrences among those receiving adjuvant radiotherapy.ConclusionOur current protocol of observation alone postoperatively for Stage IA MI − and chemoradiotherapy for Stage IA MI + is associated with a low recurrence rate. In contrast, those with Stage IB USC have a higher recurrence rate despite chemoradiotherapy, and likely require alternate treatment strategies.