Introduction/Background It is unclear if free cancer cells in fallopian tubes (FT) floaters increase with the use of uterine manipulators (UM) and whether it may increase cancer recurrence. Our objective is to assess the rate of FT floaters associated with UM use in endometrial cancer treated by MIS and its impact on oncologic outcome.

Methodology This is a single center retrospective cohort study including patients who underwent surgery for apparent early-stage endometrial cancer by either laparoscopy, robotics or laparoscopic assisted vaginal hysterectomy (LAVH) from 11/2012 to 12/2020. Data on manipulator type, isolated tumor cells (ITC), cytology, LVSI, FT floaters, stage, histology and grade were collected. Primary outcome was the rate of FT floaters. Secondary outcome was cancer recurrence and disease-specific death. Kaplan-Meier curves, univariate and multivariate logistic regression were used for statistical analysis.

Results 1,020 women with endometrial cancer were included; 876 (86%) had hysterectomy with UM and 144 (14%) without, with a mean follow-up of 44,6 months. 84,7% had endometrioid histology, 84,5 % were grade 1 or 2 and 97,2% had stage I disease. Intra-uterine balloon manipulator (V-Care) was associated with the presence of FT floaters on univariate analysis (OR 2,47; 95% CI, 1,17–5,23; p=0,018) with a rate of 14,2%. Endocervical manipulator (Hohl) was not associated with floaters (OR 0,93; 95% CI, 0,43–1,98; p=0,854) with a rate of 5,9%. No manipulator MIS had a floater rate of 6,3%. Prior tubal ligation statistically reduces the risk of floaters (OR 0,33; 95% CI, 0,17–0,65; p=0,001). On multivariate analysis, FT floaters were not associated with recurrence (OR 1,14; 95% CI, 0,486–2,68; p=0,760) and disease-specific death (OR 0,650; 95% CI, 0,116–3,65; p=0,623).

Conclusion Intra-uterine balloon manipulators used in endometrial cancer MIS is associated with higher rates of FT floaters, but were not associated with recurrence and disease-specific death. Prior tubal ligation is protective.