Main findings
This is the first study, using RA-CUSUM analysis, to evaluate the length of the learning period of robot-assisted laparoscopy on oncological outcomes. Our results suggest an institutional learning phase of at least 61 procedures, showing a decreasing recurrence rate with increasing experience. The 5-year DFS and DSS significantly improved in patients treated after this initial learning phase. The 5-year DFS and OS in our cohort are comparable with other recent studies on robot-assisted surgery in the treatment of cervical cancer6,8,14 and moreover, similar to the national recurrence and survival rates for early stage cervical cancer in The Netherlands.29 When regarding the 4.5-year DFS, the outcome parameter provided in the Laparoscopic Approach in Cervical Cancer (LACC) trial, we found that 93% of the patients treated during the experienced phase (group 2) were free of recurrence at 4.5 years of follow-up. This is substantially higher than the 4.5-year DFS of 86% reported in the MIS arm of the LACC trial.9Unfortunately, the exact MIS volume and (RA-CUSUM based) individual learning curves are unknown for the inclusion centres of the LACC trial. Furthermore, their surgical proficiency assurance was limited to providing data from (a minimum of) any 10 laparoscopic surgeries and two procedural videos, which in light of our main findings could be considered insufficient.