The Surgical Learning Curve for Prostate Cancer Control After Radical Prostatectomy

Abstract

BACKGROUND: The learning curve for surgery--i.e., improvement in surgical outcomes with increasing surgeon experience--remains primarily a theoretical concept; actual curves based on surgical outcome data are rarely presented. We analyzed the surgical learning curve for prostate cancer recurrence after radical prostatectomy. METHODS: The study cohort included 7765 prostate cancer patients who were treated with radical prostatectomy by one of 72 surgeons at four major US academic medical centers between 1987 and 2003. For each patient, surgeon experience was coded as the total number of radical prostatectomies performed by the surgeon before the patient's operation. Multivariable survival-time regression models were used to evaluate the association between surgeon experience and prostate cancer recurrence, defined as a serum prostate-specific antigen (PSA) of more than 0.4 ng/mL followed by a subsequent higher PSA level (i.e., biochemical recurrence), with adjustment for established clinical and tumor characteristics. All P values are two-sided. RESULTS: The learning curve for prostate cancer recurrence after radical prostatectomy was steep and did not start to plateau until a surgeon had completed approximately 250 prior operations. The predicted probabilities of recurrence at 5 years were 17.9% (95% confidence interval [CI] = 12.1% to 25.6%) for patients treated by surgeons with 10 prior operations and 10.7% (95% CI = 7.1% to 15.9%) for patients treated by surgeons with 250 prior operations (difference = 7.2%, 95% CI = 4.6% to 10.1%; P<.001). This finding was robust to sensitivity analysis; in particular, the results were unaffected if we restricted the sample to patients treated after 1995, when stage migration related to the advent of PSA screening appeared largely complete. CONCLUSIONS: As a surgeon's experience increases, cancer control after radical prostatectomy improves, presumably because of improved surgical technique. Further research is needed to examine the specific techniques used by experienced surgeons that are associated with improved outcomes.