Positive peritoneal cytology is highly predictive of prognosis and relapse patterns in stage III (FIGO 2009) endometrial cancer

- Positive peritoneal cytology predicts poor outcome in stage III endometrial cancer.
- Positive cytology is independently associated with risk of relapse and death.
- The excess relapses occur in the para-aortic nodes and peritoneum.

ObjectivesAccording to the updated FIGO system, positive peritoneal cytology does not affect endometrial cancer stage. This revision may reduce rates of obtaining cytology, with unclear implications in advanced disease. This study evaluates the significance of positive cytology in stage III (FIGO 2009) endometrial cancer.MethodsEligible patients received treatment for stage III endometrial cancer at a single institution and had peritoneal cytology performed.ResultsOf 196 patients, 58% were ≥ 60 years old, 48% had deep myometrial invasion, 71% lymphovascular invasion, 25% cervical invasion, 37% adnexal involvement, 79% nodal involvement, and 46% aggressive histology. Positive cytology was present in 23% (45/196) and significantly associated with cervical stromal invasion, adnexal involvement, and aggressive histology (P ≤ 0.03). There was no significant difference in rates of lymphadenectomy, chemotherapy, or radiation between negative and positive cytology groups. At a median follow-up of 47 months, the 5-year freedom from relapse was 39% for positive cytology vs. 69% for negative, disease-specific survival 42% vs. 77%, and overall survival 34% vs. 72% (P < 0.001). Positive cytology correlated with higher recurrence rates in the para-aortic nodes and peritoneum (30% vs. 9%, 23% vs. 4%; P ≤ 0.008). When controlling for adverse features including aggressive histology, positive cytology was associated with an increased hazard for relapse (HR 2.3; P = 0.002) and death (HR 2.9; P < 0.001).ConclusionsIn stage III endometrial cancer, positive cytology independently predicts outcome and is associated with distinct relapse patterns. Obtaining peritoneal cytology in stage III endometrial cancer is critical.