Clinico-pathological significance of suspicious peritoneal cytology in endometrial cancer

Abstract

<h3>Objectives:</h3> While malignant peritoneal cytology is not the component of the current cancer staging schema, the collection of a peritoneal cytologic sample at the time of hysterectomy-based surgical staging for endometrial cancer is highly endorsed by multiple societies and organizations. Suspicious peritoneal cytology refers to the result of peritoneal cytology testing that is insufficient in either quality or quantity for a definitive diagnosis of malignancy. This study examined characteristics and survival outcomes related to suspicious peritoneal cytology in endometrial cancer. <h3>Methods:</h3> A population-based retrospective study by querying the National Cancer Institute's Surveillance, Epidemiology, and End Results Program was conducted. A total of 41,229 women with stage I-III endometrial cancer who had peritoneal cytologic sampling at hysterectomy from 2010 to 2016 were examined. A Cox proportional hazard regression model and a competing risk analysis with Fine-Gray model were fitted to assess survival outcome related to suspicious peritoneal cytology. <h3>Results:</h3> Suspicious peritoneal cytology was seen in 702 (1.7%) cases. On multivariable analysis, tumors related to suspicious peritoneal cytology had distinct characteristic for T and N stages compared to negative or malignant peritoneal cytology (all, <i>P</i><0.05). In parsimonious adjustment models, suspicious peritoneal cytology was associated with increased risk of endometrial cancer mortality (subdivision-hazard ratio 1.69, 95% confidence interval 1.29-2.20, <i>P</i><0.001) and all-cause mortality (adjusted-hazard ration 1.55, 95% confidence interval 1.27-1.90, <i>P</i><0.001) and compared to negative peritoneal cytology. A sensitivity analysis demonstrated that suspicious peritoneal cytology had discrete overall survival improvement compared to malignant peritoneal cytology in a propensity score weighting model (hazard ratio 0.85, 95% confidence interval 0.72-0.99, <i>P</i>=0.049). <h3>Conclusions:</h3> Our study suggests that suspicious peritoneal cytology may be a prognostic factor for decreased survival in endometrial cancer. The results of our analysis call for a development of further studies highlighting the significance of suspicious peritoneal cytology in endometrial cancer.