Sentinel lymph node biopsy for robotic-assisted endometrial cancer staging: further improvement of perioperative outcomes

Objectives It is unclear if sentinel lymph node biopsy is associated with improved surgical outcomes compared with lymphadenectomy in patients with endometrial cancer. In this study we aimed to compare peri-operative surgical outcomes and treatment-related morbidity in patients who underwent robotic-assisted sentinel lymph node biopsy versus systematic pelvic lymphadenectomy or hysterectomy alone for apparent early-stage endometrial cancer. Methods Records were reviewed of consecutive patients with International Federation of Gynecology and Obstetrics stages I-III endometrial cancer undergoing robotic-assisted staging from January 1, 2009, through June 30, 2016. For the purpose of this analysis we focused on the actual patients who had sentinel node biopsy only (ie, excluding those who had an associated lymphadenectomy either for failed mapping or during the learning curve). We also excluded patients who had para-aortic lymph node dissection from the lymphadenectomy group. Perioperative and 30-day surgical outcomes were compared between patients who underwent sentinel lymph node assessment and those who had pelvic lymphadenectomy or hysterectomy alone, respectively. Inverse probability of treatment weighting derived from propensity scores was used to minimize allocation bias in the comparison of outcomes between groups. Results A total of 621 patients were analyzed: 188 (30.3%) with sentinel lymph node biopsy, 198 (31.9%) with pelvic lymphadenectomy, and 235 (37.8%) with hysterectomy alone. Inverse probability of treatment weights analysis balanced for baseline characteristics (age, body mass index, American Society of Anesthesiologists score, Charlson co-morbidity index, parity, prior cesarean section, and previous abdominal operation) showed no significant differences in intra-operative and post-operative complications, re-admissions, and re-operations between the groups. Compared with pelvic lymphadenectomy, the sentinel lymph node biopsy group had a shorter mean operative time (138.0 vs 222.8 min, p<0.001) and less median blood loss (50 vs 100 mL, p<0.001). Sentinel lymph node biopsy also was not associated with worse morbidity compared with hysterectomy alone. Conclusions Introduction of sentinel lymph node biopsy reduces operative times and improves peri-operative surgical outcomes of robotic-assisted staging for apparent early-stage endometrial cancer without worsening the morbidity of hysterectomy alone.