The primary treatment for early-stage, low-grade endometrial cancer is a total laparoscopic hysterectomy (TLH) with bilateral salpingo-oophorectomy (BSO)^1–3. During this procedure, uterine manipulators are commonly used. These instruments facilitate transection of uterine pedicles, delineation of vaginal fornices, colpotomy, and maintenance of pneumoperitoneum^4,5. Amongst the numerous manipulators available, the vast majority possesses an intrauterine (IU) tip. Only few are without IU tip, such as the McCartney tube⁶. Especially manipulators with tip provide the added advantage of optimal uterine mobilization and enhanced exposure of the surgical field. Therefore, using IU manipulators may minimalize damage during surgery to surrounding tissues, including the ureters⁴. However, the use of uterine devices for malignant diseases has been subject to controversy. Some surgeons have argued that using IU manipulators may cause iatrogenic lymph vascular space invasion (LVSI) and spillage of malignant cells into the peritoneal cavity, which have both been associated with poor outcome in endometrial cancer^7–11.

Several studies demonstrated that using IU manipulators during hysterectomy did not influence the incidence of LVSI, peritoneal cytology, recurrence rate, and survival in endometrial cancer^12–14. On the contrary, Padilla-Iserte et al. previously showed that oncological outcome was worse when IU manipulators were used in terms of recurrence rate and survival. However, this association was only observed in early-stage cancer¹⁵. In line with the latter results, Siegenthaler et al. showed that positive peritoneal cytology (PPC) conversion occurred in 8% of endometrial cancer patients following laparoscopic surgery with IU manipulators, which had a negative impact on oncological outcome¹⁶.

While there has been growing interest in the effect of uterine manipulators on oncological outcome in endometrial cancer, none of the previous studies specifically compared IU with non-IU manipulators. IU manipulators are theoretically more likely to cause dissemination of tumour cells than non-IU manipulators due to potential tumour manipulation. In light of this, it should be stressed that the introduction of TLH as a safe approach for endometrial cancer is predominantly based on studies in which non-IU manipulators were used^1,2,17. Furthermore, while tumour stage, grade, and histotype are important prognostic factors, most of the studies did not restrict their focus to one consistent subset of patients.

The aim of this study was to determine whether hospital manipulator preference for IU manipulators or non-IU manipulators during TLH influences oncological outcome in early-stage, low-grade endometrioid endometrial cancer (EEC).