Abstract
BACKGROUND: Pure uterine serous carcinoma (p-USC) and mixed tumors with serous component (m-USC) are aggressive subtypes of endometrial cancer associated with high mortality rates. This retrospective study aimed to compare clinicopathologic features and outcomes of p-USC and m-USC in a single center. METHODS: This study retrospectively reviewed patients diagnosed with USC at Peking University People's Hospital between 2008 and 2022. T-tests and chi-square tests were used to compare clinicopathological characteristics between p-USC and m-USC. Kaplan-Meier survival curve and Cox regression analysis were used to analyze the impact of clinical and pathological variables on OS and PFS. RESULTS: Among the 91 patients who underwent surgery, 65.9% (n = 60) were p-USC, and 34.1% (n = 31) were m-USC. Patients with p-USC had earlier menopause (P = 0.0217), a lower rate of progesterone receptor(PR) expression (P < 0.001), and were more likely to have positive peritoneal cytology (P = 0.0464). After a median follow-up time of 40 months, 28 (46.7%) p-USC and 9 (29%) m-USC patients had progression disease, 18 (30%) and 8 (25.8%) patients died of their disease. 5-year PFSR were 51.2% and 75.3%, respectively, and 5-year OS rates were 66% and 67.4%. Kaplan-Meier survival analysis showed that p-USC was more likely to relapse than m-USC (P = 0.034), but there was no significant difference in OS. Cox regression analysis showed that lymph node metastasis and surgical approach were risk factors for OS, and myoinvasion depth ≥ 1/2 was an independent risk factor for PFS. CONCLUSIONS: p-USC was more likely to relapse than m-USC, but there was no significant difference in OS between the two subtypes.