Association of peritoneal cytology with other prognostic factors in endometrial cancer

Purpose: It is still debatable whether surgical staging of endometrial cancer (EC) should include sampling of peritoneal cytology (PC) and for what purpose this should be done. The aim of our study was to determine the significance of peritoneal cytology in EC and its association with other histological and clinical parameters. Methods: This is a retrospective study that comprises of results from 357 patients with EC that were operated in our center in the previous nine years. Patients were divided into two groups: the first group with a positive and the second group with a negative PC. Results: Malignant cells were found in the peritoneal cytology of 23 patients (6.4%), while 334 patients (93.6%) had negative PC. There was no significant difference in patients' age between the two groups (p = 0.20). Peritoneal cytology was more prevalent in the non-endometrioid than the endometrioid subtype of EC (p = 0.00). There was a significant statistical difference (p = 0.00) in malignant PC in stages where cancer is confined to the uterus (International Federation of Gynecologists and Obstetricians (FIGO) stages I and II) compared with those where cancer has metastasized outside the uterus (stages III and IV). Most of the patients with malignant PC (69.6%) had high-grade disease (G3). Conclusion: Malignant peritoneal cytology is associated with other negative prognostic factors in endometrial cancer (histological grade, FIGO stage, and non-endometrioid histological subtypes). Based on these findings, we encourage sampling of peritoneal washing in all EC patients and consider it mandatory in patients with non-endometrioid subtype, high-grade histology, and in advanced FIGO stage.