THE SELECTION OF CANDIDATES TO ROBOT-ASSISTED RADICAL
PROSTATECTOMY IS STRONGLY AFFECTED BY SURGICAL
EXPERIENCE: RESULTS FROM A TERTIARY REFERRAL CENTER.
Introduction. Previous studies showed that the prostate cancer (PCa) patients
receiving robot-assisted radical prostatectomy (RARP) have better baseline
characteristics compared to their open counterparts. These findings might be related
to the learning-curve phenomenon typical of early adopters, where less experienced
surgeons are more likely to treat patients with more favorable disease. We
hypothesized that these observations do not apply to experienced surgeons.
Methods. Overall, 1,265 patients with PCa treated with RARP by the seven surgeons
at a single tertiary referral center between February 2006 and August 2013 were
identified. No patient received neo-adjuvant or adjuvant therapies. All patients had
preoperative and pathological data available. Surgical volume was coded as the
number of robotic cases done by the surgeon before the index patient’s operation.
Associations between patient characteristics and surgeon experience were tested using
linear regression (age, and PSA) or ordinal logistic regression (Charlson comorbidity
index [CCI], clinical stage, biopsy Gleason score, and D’Amico risk group). These
models were fitted with general estimation equations for clustering among surgeons.
Results. Mean patient age was 62.5 years (median: 63). Mean surgical volume was
182 (median: 173; interquartile range [IQR]: 62-289). There was no association
between surgeon experience and age, CCI, and preoperative PSA (all P≥0.4). We
observed a statistically significant association between surgeon experience and
clinical stage, biopsy Gleason score, and risk group, with more experienced surgeons
less likely to treat patients with clinical stage ≤T2a, biopsy Gleason score ≤6, and
low-risk disease (all P≤0.002). Particularly, the proportion of patients with clinical
stage ≤T2a decreased from 75.9 to 60.5% for surgeons who have done less than 100
and more than 300 procedures, respectively (P<0.001). Similarly, the proportion of
patients with biopsy Gleason score ≤6 decreased from 77.3 to 63.6%, respectively
(P<0.001). Finally, the proportion of patients with low-risk disease decreased from
54.3 to 37.1%, respectively (P<0.001). On the other hand, the proportion of patients
with high-risk disease almost doubled (from 5.3 to 9.0%) for surgeons who have done
less than 100 and more than 300 procedures, respectively (P<0.001).
Discussion. While less experienced surgeons are more likely to treat patients with
favorable disease, the likelihood of performing surgery in patients with high-risk PCa
increased with surgical experience, presumably because of improved surgical
technique.
Conclusions. The increase in surgical experience with robotic surgery leads to the
treatment of patients with more aggressive disease characteristics.