Suspicious Positive Peritoneal Cytology (Class III) in Endometrial Cancer Does Not Affect Prognosis

Positive peritoneal cytology is a poor prognostic factor in patients with advanced endometrial cancer. Suspicious positive peritoneal cytology (class III) is commonly encountered in clinical practice. However, no standard treatment protocol exists for its management. Here, we investigated a possible relationship between suspicious positive peritoneal cytology, disease stage, risk factors, and endometrial cancer prognosis. We included patients diagnosed with endometrial cancer who underwent total hysterectomy and peritoneal cytology at the University of Tokyo Hospital between 2008 and 2022. Overall, 670 patients were included in the analyses; both demographic and clinical data of the patients were collected. The proportion of patients with lymph node metastasis was significantly different between peritoneal cytology groups, showing lymph node metastasis to be more extensive in patients with positive or suspicious positive peritoneal cytology than in patients with negative peritoneal cytology (p < 0.05). Thirty-nine patients had suspicious positive peritoneal cytology. Omental resection and biopsy were performed in 16 cases. No case of omental metastasis was found. Among patients with suspected ascites cytology, no patient experienced symptom recurrence or death. Therefore, monitoring lymph node metastasis in suspicious positive cases is essential. Moreover, a change of treatment method based on the finding of suspected positive peritoneal cytology is not necessary.