Peritoneal cytology: a risk factor of recurrence for non-endometrioid endometrial cancer

We compared the impact of positive peritoneal cytology on prognosis between patients with endometrioid and non-endometrioid endometrial carcinoma.

We retrospectively reviewed the medical records of 490 patients diagnosed with endometrial cancer between 2000 and 2012. These patients were divided into two groups: endometrioid and non-endometrioid histologies. We compared the patients' baseline characteristics, tumor recurrence patterns, and survival to determine the prognostic factors and how they differed between the two groups.

Of the included patients, 448 had endometrioid histology and 42 had non-endometrioid histology. A total of 27 patients experienced tumor recurrence: 17 with endometrioid histology (4.0%) and 10 with non-endometrioid histology (23.8%). Compared to endometrioid type, non-endometrioid type exhibited higher rates of recurrence (p<0.01). Recurrence sites of the non-endometrioid group were mainly peritoneal seeding (p<0.01) and distant organ metastasis (p=0.02). Risk factors for tumor recurrence included patient age, stage of disease, and adjuvant treatment for endometrioid type. On the other hand, in cases of non-endometrioid endometrial cancer, positive peritoneal cytology was an independent prognostic factor regardless of tumor stage (HR, 15.34; 95% CI, 3.55-66.25; p<0.01). Among cases with non-endometrioid histology, median recurrence-free survival significantly differed between the negative peritoneal cytology group and the positive peritoneal cytology group (120 months versus 22 months, respectively; p<0.01).

Positive peritoneal cytology is an independent prognostic factor for patients with non-endometrioid endometrial cancer.