Background The prognostic factors of uterine serous carcinoma (USC) vary among studies, and there is no report of Chinese USC patients.

Objective The aim of this study was to investigate the clinicopathological characteristics and prognostic factors in Chinese patients with USC.

Methods Patients with USC from 13 authoritative university hospitals in China and treated between 2004 and 2014 were retrospectively reviewed. Three-year disease-free survival rate (DFSR), cumulative recurrence, and cumulative mortality were estimated by Kaplan-Meier analyses and log-rank tests. Multivariate Cox regression analysis was used to model the association of potential prognostic factors with clinical outcomes.

Results Data of a total of 241 patients were reviewed. The median follow-up was 26 months (range, 1–128 months). Median age was 60 years (range, 39–84 years), and 58.0% had stages I–II disease. The 3-year DFSR and cumulative recurrence were 46.8% and 27.7%. Advanced stage (III and IV) (P = 0.004), myometrial invasion (P = 0.001), adnexal involvement (P < 0.001), lymph node metastasis (P = 0.025), and positive peritoneal cytology (P = 0.007) were independently associated with 3-year DFSR. Advanced stage (P = 0.017), myometrial invasion (P = 0.008), adnexal involvement (odds ratio, 2.987; P = 0.001), lymph node metastasis (P = 0.031), and positive peritoneal cytology (P = 0.001) were independently associated with the cumulative recurrence. Myometrial invasion (P = 0.004) and positive peritoneal cytology (P = 0.025) were independently associated with 3-year cumulative mortality.

Conclusions Peritoneal cytology and myometrial invasion could be independent prognostic factors for 3-year DFSR, cumulative recurrence, and cumulative mortality of patients with USC. Prospective studies are needed to confirm these results.