Positive peritoneal cytology and recurrence patterns in endometrial cancer according to postoperative recurrence risk...

The clinical significance of positive peritoneal cytology (PPC) in endometrial cancer remains controversial, particularly in low-risk disease. This study investigated the distribution of PPC across postoperative recurrence risk groups and its associations with clinicopathological features, recurrence patterns, menopausal status, and exploratory survival outcomes.

We retrospectively analyzed 757 patients with endometrial cancer who underwent hysterectomy between 2002 and 2021. Clinicopathological characteristics, recurrence patterns, and exploratory survival outcomes were evaluated according to peritoneal cytology status within postoperative recurrence risk groups.

PPC was observed in 29.9% of patients, including 20.0% of the low-risk group. PPC was associated with adverse pathological features, including advanced stage, lymphovascular space invasion, deep myometrial invasion, cervical stromal invasion, and adnexal involvement. PPC was more frequent among premenopausal patients. However, among patients with PPC, menopausal status was not associated with progression-free survival (PFS) or overall survival (OS). PPC was associated with peritoneal recurrence in the overall cohort (9.3% vs. 1.9%, P < 0.001), with a trend in the low-risk group (P = 0.057). In exploratory multivariable analyses, PPC was associated with shorter PFS in the low-risk group (P = 0.009) but not with OS.

PPC was observed across all postoperative recurrence risk groups, including low-risk disease, and was associated with adverse clinicopathological features and peritoneal recurrence. The higher frequency of PPC in premenopausal patients, despite no association between menopausal status and prognosis among cytology-positive patients, suggests heterogeneity in the mechanisms underlying cytological positivity. These findings are hypothesis-generating and require prospective validation.