Objective: We aimed to investigate whether positive peritoneal cytology could serve as a prognostic factor in endometrial cancer (EC).
Methods: From patients with EC surgically treated at Peking University People's Hospital between 2006 and 2016, 520 patients were selected for retrospective investigation. Clinical and pathologic factors associated with positive peritoneal cytology were assessed using univariate and multivariate logistic regressions model. Disease-free survival (DFS) and overall survival (OS) were evaluated using Kaplan-Meier estimation and multivariate Cox regressions model.
Results: (i) The incidence of positive peritoneal cytology in EC patients was 9.0% (47/520). (ii) Multivariate analysis showed that the independent risk factors of positive peritoneal cytology were nonendometrioid carcinoma (odds ratio [OR] = 4.0, 95% confidence interval [CI], 1.8-8.8, P = 0.001), tumor diameter ≥2 cm (OR = 3.2, 95% CI, 1.2-8.7, P = 0.023), cervical stromal invasion (OR = 2.9, 95% CI, 1.3-6.6, P = 0.009) and distant metastasis (OR = 6.5, 95% CI, 1.7-25.4, P = 0.007). (iii) The 5-year DFS and 5-year OS of the positive peritoneal cytology group were significantly lower compared with the negative group (54.0% vs 93.2%, P < 0.001; 63.6% vs 94.6%, P < 0.001). (iv) After other contributing factors were adjusted in the multivariable model, positive peritoneal cytology remained an independent predictor of decreased DFS (OR = 2.8, 95% CI, 1.3-6.0, P = 0.007) and OS (OR = 2.8, 95% CI, 1.0-7.2, P = 0.035).
Conclusion: Positive peritoneal cytology was an independent risk factor in EC patients. Even though it is no longer an indicator according to the current International Federation of Gynecology and Obstetrics staging system, the peritoneal cytology status should still be considered for accurate risk stratification in EC.
Keywords: endometrial neoplasms; gynecology; postoperative period.