Elsevier

The Lancet Oncology

Volume 10, Issue 5, May 2009, Pages 475-480
The Lancet Oncology

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The surgical learning curve for laparoscopic radical prostatectomy: a retrospective cohort study

https://doi.org/10.1016/S1470-2045(09)70079-8Get rights and content

Summary

Background

We previously reported the learning curve for open radical prostatectomy, reporting large decreases in recurrence rates with increasing surgeon experience. Here we aim to characterise the learning curve for laparoscopic radical prostatectomy.

Methods

We did a retrospective cohort study of 4702 patients with prostate cancer treated laparoscopically by one of 29 surgeons from seven institutions in Europe and North America between January, 1998, and June, 2007. Multivariable models were used to assess the association between surgeon experience at the time of each patient's operation and prostate-cancer recurrence, with adjustment for established predictors.

Findings

After adjusting for case mix, greater surgeon experience was associated with a lower risk of recurrence (p=0·0053). The 5-year risk of recurrence decreased from 17% to 16% to 9% for a patient treated by a surgeon with 10, 250, and 750 prior laparoscopic procedures, respectively (risk difference between 10 and 750 procedures 8·0%, 95% CI 4·4–12·0). The learning curve for laparoscopic radical prostatectomy was slower than the previously reported learning curve for open surgery (p<0·001). Surgeons with previous experience of open radical prostatectomy had significantly poorer results than those whose first operation was laparoscopic (risk difference 12·3%, 95% CI 8·8–15·7).

Interpretation

Increasing surgical experience is associated with substantial reductions in cancer recurrence after laparoscopic radical prostatectomy, but improvements in outcome seem to accrue more slowly than for open surgery. Laparoscopic radical prostatectomy seems to involve skills that do not translate well from open radical prostatectomy.

Funding

National Cancer Institute, the Allbritton Fund, and the David J Koch Foundation.

Introduction

Surgical procedures are often highly complex, and it is reasonable to suppose that a surgeon must build experience with a procedure before being able to do it optimally. As such, the learning curve is a ubiquitous concept among surgeons. However, most studies of surgical learning curves have focused on improvements in technical aspects, such as operating time1 and blood loss.2 Such endpoints are less relevant to patients than those related to the reason for their operation, such as relief of symptoms, improvement of function, or cure of cancer.

Previously, we analysed data from 7765 patients treated with open radical prostatectomy to calculate a learning curve for surgical efficacy, defined in terms of prostate-cancer recurrence. The probability of recurrence initially dropped steeply then reached a plateau once a surgeon had done about 250–350 operations.3 We subsequently reported that the learning curve for organ-confined cancer approached a zero recurrence rate for the most experienced surgeons (1500 or more operations).4 This suggests that cancer recurrence in patients treated with open radical prostatectomy is largely the result of limitations in surgical technique, and that the plateau in our original report was driven by disseminated disease in locally advanced cancer.4

In the present study we report the learning curve for laparoscopic radical prostatectomy. This serves as a replication study on an independent (and international) cohort, and enables us to make comparisons between open and laparoscopic learning curves.

Section snippets

Patients

Previously, we established a multicentre, international retrospective cohort of patients treated by laparoscopic radical prostatectomy, without robotic assistance.5 Seven participating institutions (Cleveland Clinic Foundation, USA; Institut Mutualiste Montsouris, France; Memorial Sloan-Kettering Cancer Center, USA; Hospital Universitario La Paz, Spain; Klinikum Heibronn, Germany; Lahey Clinic, USA; and Krankenhaus der Elisabethinen, Austria) provided recurrence data for a cohort of 5328

Results

The distribution of surgeons by the total number of lifetime operations is shown in table 1. Although many of the surgeons had done fewer than 50 laparoscopic radical prostatectomies (the fewest number performed was two), around half had done more than 100 procedures, with a maximum experience of 1066 procedures. Clinical and pathological information of patients is shown in table 2, stratified by surgeon experience. 30% of patients (1404 of 4702) were seen by a surgeon who had done less than

Discussion

The probability of recurrence after laparoscopic radical prostatectomy decreases as the experience of the operating surgeon increases. In addition to replicating the radical prostatectomy learning curve on an independent dataset, our data enable us to compare learning curves between open and laparoscopic surgical approaches. Surgical outcome seems to improve more slowly for laparoscopic than for open surgery.

There are several possible explanations for this observation. First, laparoscopic

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