Ultrasensitive Prostate Specific Antigen Assay Following Laparoscopic Radical Prostatectomy – An Outcome Measure for Defining the Learning Curve

Abstract

Ann R Coll Surg EnglRadical retropubic prostatectomy (RRP) performed laparoscopically is a popular treatment with curative intent for organ-confined prostate cancer. After surgery, prostate specific antigen (PSA) levels drop to low levels which can be measured with ultrasensitive assays. This has been described in the literature for open RRP but not for laparoscopic RRP. This paper describes PSA changes in the first 300 consecutive patients undergoing non-robotic laparoscopic RRP by a single surgeon. OBJECTIVES To use ultrasensitive PSA (uPSA) assays to measure a PSA nadir in patients having laparoscopic radical prostatectomy below levels recorded by standard assays. The aim was to use uPSA nadir at 3 months' post-prostatectomy as an early surrogate end-point of oncological outcome. In so doing, laparoscopic oncological outcomes could then be compared with published results from other open radical prostatectomy series with similar end-points. Furthermore, this end-point could be used in the assessment of the surgeon's learning curve. PATIENTS AND METHODS Prospective, comprehensive, demographic, clinical, biochemical and operative data were collected from all patients undergoing non-robotic laparoscopic RRP. We present data from the first 300 consecutive patients undergoing laparoscopic RRP by a single surgeon. uPSA was measured every 3 months post surgery. RESULTS Median follow-up was 29 months (minimum 3 months). The likelihood of reaching a uPSA of ≤ 0.01 ng/ml at 3 months is 73% for the first 100 patients. This is statistically lower when compared with 83% (P < 0.05) for the second 100 patients and 80% for the third 100 patients (P < 0.05). Overall, 84% of patients with pT2 disease and 66% patients with pT3 disease had a uPSA of ≤ 0.01 ng/ml at 3 months. Pre-operative PSA, PSA density and Gleason score were not correlated with outcome as determined by a uPSA of ≤ 0.01 ng/ml at 3 months. Positive margins correlate with outcome as determined by a uPSA of ≤ 0.01 ng/ml at 3 months but operative time and tumour volume do not (P < 0.05). Attempt at nerve sparing had no adverse effect on achieving a uPSA of ≤ 0.01 ng/ml at 3 months. CONCLUSIONS uPSA can be used as an early end-point in the analysis of oncological outcomes after radical prostatectomy. It is one of many measures that can be used in calculating a surgeon's learning curve for laparoscopic radical prostatectomy and in bench-marking performance. With experience, a surgeon can achieve in excess of an 80% chance of obtaining a uPSA nadir of ≤ 0.01 ng/ml at 3 months after laparoscopic RRP for a British population. This is equivalent to most published open series.

The Learning Curve for Laparoscopic Radical Prostatectomy: An International Multicenter Study

“…This is largely because previous authors have focused on outcomes of only indirect medical importance (blood loss, operating time) and have used analytic methods with predetermined cut points. For example, if the investigator divides surgeon experience into categories of 0 to 99, 100 to 199 and 200 to 299, 4,5 then clearly the minimum number of procedures required per surgeon will be a number divisible by 100. Moreover investigators have typically reported the results from single surgeon series.…”

“…Moreover investigators have typically reported the results from single surgeon series. 4,6,7 Conversely in this study we focused on an end point of oncologic relevance, that is SMs, we used nonlinear modeling to present the LC graphically and we included data from a large number of surgeons at multiple institutions.…”

68Ga-HBEDD PSMA-11 PET/CT staging prior to radical prostatectomy in prostate cancer patients: Diagnostic and predictive value for the biochemical response to surgery

“…[18][19][20] However, many patients fail to achieve an undetectable PSA (<0.03 ng ml −1 ) following RP, with 14-34% of patients failing to respond at the first post-operative PSA reading. [2][3][4][5][6] Information that predicts how well a patient responds to surgery is beneficial when weighing up the pros of curative treatment against the cons of unwanted side-effects. Patients who fail to respond following RP are likely to experience continuously rising PSA levels requiring additional treatments with their attendant morbidities in addition to those of the primary treatment.…”

Laparoscopic radical prostatectomy outcome data: how should surgeon’s performance be reported? A retrospective learning curve analysis of two surgeons

“…While a follow-up study might be proposed which includes the five-year biochemical recurrence (BCR) rates and continence data, it is beneficial that this study has used outcomes immediately available for a continuous record of performance. This would also be facilitated by the use of new early markers such as ultrasensitive PSA [ 31 ].…”