Prospective Multicenter Trial Assessing the Impact of Positive Peritoneal Cytology Conversion on Oncological Outcome in Patients with Endometrial Cancer Undergoing Minimally Invasive Surgery with the use of an Intrauterine Manipulator: Positive Peritoneal Cytology Conversion and Its Association with Oncological Outcome in Endometrial Cancer

BACKGROUND: Minimally invasive surgery is the standard approach in early-stage endometrial cancer according to evidence showing no compromise in oncological outcomes, but lower morbidity compared with open surgery. However, there are limited data available on the oncological safety of the use of intrauterine manipulators in endometrial cancer. PATIENTS AND METHODS: This prospective multicenter study included patients with endometrial cancer undergoing laparoscopic staging surgery with the use of an intrauterine manipulator. We obtained three different sets of peritoneal washings: at the beginning of the surgical procedure, after the insertion of the intrauterine manipulator, and after the closure of the vaginal vault. The rate of positive peritoneal cytology conversion and its association with oncological outcomes was assessed. RESULTS: A total of 124 patients were included. Peritoneal cytology was negative in 98 (group 1) and positive in 26 (group 2) patients. In group 2, 16 patients presented with positive cytology at the beginning of the surgery (group 2a) and 10 patients had positive cytology conversion during the procedure (group 2b). Recurrence rate was significantly different among the study groups, amounting to 9.2%, 25.0%, and 60.0% for groups 1, 2a, and 2b, respectively (p < 0.001). Group 1 showed the best recurrence-free and overall survival, followed by group 2a, while patients in group 2b had the worst oncological outcomes (p = 0.002 and p = 0.053, respectively). Peritoneal cytology was an independent predictor of recurrence and death on multivariable analysis. CONCLUSION: A total of 8.1% of patients with endometrial cancer undergoing minimally invasive surgery with intrauterine manipulation showed positive peritoneal cytology conversion associated with significantly worse oncological outcome.