The learning curve for laparoscopic extended pelvic lymphadenectomy for intermediate- and high-risk prostate cancer: implications for compliance with existing guidelines.

OBJECTIVE: To investigate the learning curve for performing extended pelvic lymphadenectomy (ePLND) during laparoscopic radical prostatectomy (LRP) in patients with intermediate- and high-risk prostate cancer. PATIENTS AND METHODS: In all, 500 patients underwent ePLND for intermediate- or high-risk prostate cancer by one surgeon during a 48-month period. A transperitoneal laparoscopic approach was used in all patients to allow adequate access to the internal iliac vessels. The variables chosen as being the most important discriminators of the quality of ePLND were operating time, complication rate and lymph node (LN) yield. The learning curves for ePLND were calculated using the cumulative sum and cumulative average methods and the number of procedures performed until attainment of acceptable failure rates (competence levels) was calculated. LN parameters were compared with the results from the preceding 311 cases where limited PLND was undertaken. RESULTS: The median (range) preoperative PSA level was 8.0(1-62.5) ng/mL and biopsy Gleason score was 7(6-10). In all, 64% of patients had intermediate-risk and 36% had high-risk prostate cancer. There were no intraoperative blood transfusions and no conversions to open surgery. The median (range) blood loss was 200(10-1400) mL and the postoperative transfusion rate was 1.6%. The operating time fell at a steady rate of 2.7% after the 15th case and plateaued after 130 patients. At competence levels of 5% and 10%, the learning curve for all complications ended after 346 and 136 patients, respectively. At a 5% competence level the learning curve for PLND-specific complications was 40 cases and there was no learning curve at a 10% competence level. The overall complication rate was 7.2% of which almost half (47%) were deemed to be PLND-specific. The cumulative average of the LN counts plateaued after 150 procedures. Furthermore, the median LN count after ePLND was more than double that of the authors' historical standard PLND controls (14 vs 6, P < 0.001) and increased with experience up to the end of the series (9 to 20). The likelihood of LN involvement (LNI) correlated with biopsy and pathological Gleason grade, clinical and pathological stage and d'Amico risk group. CONCLUSIONS: This study suggests a learning curve of ≈130 cases for operating time, 136 cases for all complications, 40 cases for PLND-specific complications and 150 cases for LN yield. The risk of LNI for patients with intermediate- and high-risk prostate cancer was 8.4% and 19.4%, respectively, which suggests that a significant proportion would benefit from ePLND. It also shows that ePLND can be safely incorporated into LRP, and therefore also into robot-assisted RP, in a high-volume setting.