The comparison of pure uterine serous carcinoma and mixed tumor with serous component：A Single-Institution Review of 91 Cases

Abstract

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 of p-USC and m-USC in a single center and to identify risk factors associated with overall survival (OS) and progression-free survival (PFS). 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). Kaplan-Meier survival analysis showed that p-USC was more likely to relapse than m-USC (P=0.028), but there was no significant difference in OS. In general, 48.4% (n=44) of all patients diagnosed with USC were in early stage (I+II), the recurrence rate was 18.0%, and the 5-year OS was 84.8%. 36.3% (n=33) were in stage III, the recurrence rate was 53.1%, and the 5-year OS was 52.6%. 15.3% (n=14) were in stage IV, the recurrence rate was 89.7%, and the 5-year OS was 33.3%. 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. Lymph node status, surgical approach, and myoinvasion depth were identified as important prognostic factors for all patients diagnosed with USC, regardless of p-USC or m-USC status.