Introduction In patients who respond to neoadjuvant chemotherapy (NACT) for advanced-stage epithelial ovarian cancer (EOC), minimally invasive surgery (MIS) may reduce the morbidity of surgery. Studies evaluating oncologic outcomes of minimally invasive interval cytoreductive surgery are largely retrospective.

Methods LANCE is a prospective, multicenter, international, randomized trial evaluating whether MIS is non-inferior to laparotomy in terms of disease-free survival, among patients with stage IIIC and IV EOC with normalization of CA125 after 3–4 cycles of NACT. The planned 100 patients were enrolled in a lead-in phase to assess the feasibility of the trial with respect to cross-over among those assigned to MIS, complete gross resection, and recruitment. Patients were randomized (1:1) to undergo open or MIS (laparoscopic or robotic) surgery. Surgeons applied maximal effort to resect all visible tumor, conversion to open surgery was performed when necessary to attain complete resection.

Results From September 2020-February 2023, 100 patients were randomized (51 open, 49 MIS). The mean age was 62 years, 67% had stage IIIC, and 54% received 3 cycles of NACT. Six patients randomized to MIS (12.2%;95%CI: 4.6–24.8%) underwent conversion to open surgery. Surgeons achieved complete gross resection in 87.5% (95%CI: 74.8–95.3%) and 83% (95%CI: 69.2–92.4%) of patients assigned to MIS and open (p=0.6). There were three (6.3%) intraoperative complications in the MIS group and three (6.4%) in the open group. Two patients (4.1%) in the MIS group experienced grade 4–5 adverse events following surgery.

Conclusion/Implications Evaluation of MIS interval cytoreductive surgery is feasible, enrollment is ongoing in a definitive trial.