Introduction/Background*Uterine serous carcinoma (USC) accounts for 10% of all endometrial cancer; however, it carries the poorest prognosis, with 5-year survival rates as low as 55%. According to NCCN guidelines first-line treatment is comprehensive surgical staging by laparotomy/laparoscopy, and maximal cytoreduction to no residual disease in advanced stages. However, due to the rarity and unfavorable prognosis of the disease, available evidence is scanty and controversial on risk factors staging, adjuvant treatment, and outcome of USC.

Therefore, a retrospective study on women with USC undergoing surgery was performed to better elucidate oncologic outcomes of these patients.

Methodology This is a retrospective analysis of a prospectively collected database of consecutive patients with USC who underwent surgery between 2000-2020 at a tertiary referral center for gynecologic oncology. The primary objective of this study were progression-free (PFS) and overall survival (OS) outcomes, evaluated using Kaplan-Meier and Cox proportional hazard models.

Result(s)*147 consecutive patients were finally included in the study. Median (IQ range) age and BMI were 66 (39-71) years and 25 (39-71) kg/m², respectively. Stage distribution was as follows: 67 (45.6%) with early stage (stage I/II) with uterine confined disease and 80 (54.4%) with advanced stages (stage III/IV) disease. The median follow-up period was 78.6 months (IQ range = 35.7-117.3 months). The overall recurrence rate was 41% (60 patients), early-stage disease recurrence was 28.4% (19 out of 67) while advanced stage disease recurrence was 51.3% (41 out of 80). The 5-year PFS rate was 35.0% (95% confidence interval [CI]: 27.5-44.7%). At multivariate analysis, age, BMI, depth of myometrial invasion, cytology, and optimal cytoreduction with postoperative residual tumor absence significantly influenced PFS. The 5-year OS rates were 46.5% (95% CI: 38.1-56.8]. Multivariate analysis showed that optimal cytoreduction and accuracy of retroperitoneal surgery were the only two variables influencing OS.

Conclusion*Among patients with apparent early-stage USC, peritoneal and retroperitoneal staging allows to identify those with disease harboring outside the uterus. Comprehensive surgical staging and optimal cytoreduction are the most significant prognostic factors affecting survival. Further collaborative studies are warranted in order to improve outcomes of serous endometrial cancer patients.