Objective: To determine the correlation between positive peritoneal cytology (PPC) and lymph node metastasis in patients with endometrial cancer grossly confined to the uterus.
Methods: Data were extracted from the Surveillance, Epidemiology, and End Results database between 1988 and 2005. Only patients with endometrial cancer grossly confined to the uterus who had undergone a complete staging procedure (lymph node removal) were included. Statistical analysis used the χ2 test and logistic regression models.
Results: A total of 22,947 patients were identified. Positive peritoneal cytology was present in 3.5% of the patients. The incidence of lymph node metastasis was significantly higher among patients with PPC compared to those with negative peritoneal cytology for all histologic types examined (P < 0.0001): endometrioid adenocarcinoma, 28.7% versus 6.9%; adenocarcinoma not otherwise specified, 35.4% versus 5.8%; clear cell/serous carcinoma, 41.4% versus 19.0%, and carcinosarcoma,; 38.4% versus 14.4%. After adjusting for other contributing factors in the multivariable model, PPC remained an independent predictor of lymph node metastasis (P < 0.0001).
Conclusion: Our data indicate that patients with positive washings are at significant risk of nodal metastasis and adverse prognosis. Although no longer a part of the current International Federation of Gynecology and Obstetrics staging criteria, peritoneal cytology status should continue to inform clinical decision making in endometrial cancer.