San Francisco--More experienced surgeons have more positive outcomes.
That may be an intuitive assumption, but data on radical prostatectomy outcomes appear to back it up. After a median follow-up period of 50 months, researchers at Memorial Sloan-Kettering Cancer Center, New York, found that surgical volume is an independent variable associated with disease-free survival. A patient's risk for biochemical relapse 5 years after surgery, after controlling for case mix, is decreased by increased surgeon experience. The results mirror earlier studies that looked at morbidity and mortality within 30 days of surgery.
"Surgical experience has a significant impact on cancer-free survival following radical prostatectomy," said lead author Fernando Bianco, MD, a urologic oncology fellow at Sloan-Kettering working with Peter T. Scardino, MD, and colleagues. "Surgical experience and technique play a real role in patient outcome."
The researchers evaluated 7,535 consecutive patients who received radical prostatectomy from one of 65 surgeons at four high-volume institutions between 1987 and 2003. Traditional analysis indicates that biological factors such as tumor stage, grade, and PSA are the key factors in long-term survival. Researchers found that the familiar biological elements do play the predominant role in patient outcome. However, the surgeon's experience emerged as another key and independent variable associated with cancer-free outcomes.
A meta-analysis controlling for case mix, PSA, Gleason score, stage, positive margin, and surgical expertise revealed a positive correlation between surgical experience and biochemical recurrence. Extracapsular extension, seminal vesicle invasion, nodal metastasis, positive margins, Gleason score, and PSA were also independent predictors for recurrence.
Learning curve never levels off
Among the surgeons included in the study, 26 had performed more than 40 radical prostatectomies during the 6-year review period and 14 had performed more than 100 procedures. After a median follow-up of 50 months, 1,281 patients (17%) had an increase in PSA.
"There is an ascending learning curve that flattens, but never really levels off," Dr. Bianco said.
Surgeons who have performed fewer than 40 radical prostatectomies in their lifetime had significantly more recurrences than those who had done the procedure more frequently. The impact of experience was less pronounced after 250 cases. However, there was no point along the learning curve at which more experience did not translate into better outcomes.
But while more experienced surgeons produced better outcomes, the study also found that not all experience is equal. There was significant variation in outcomes between surgeons with similar experience levels. The meta-analysis showed that 54% of the difference in outcome between surgeons of similar experience is due to differences in skill and technique. The remaining difference can be explained by chance.
Results were re-analyzed after excluding surgeons who had performed fewer than 100 radical prostatectomies to determine the sensitivity of the analysis. Among the most experienced surgeons in the study, 73% of the differences in patient outcome are related to individual surgeon skill and technique.
"These results suggest that there are aspects of this surgical procedure where cancer control outcomes will depend on the approach, for example, the extent of lymph node dissection," Dr. Bianco concluded.
"The implications are quite significant when you look at long-term outcomes," commented Howard Scher, MD, chief of genitourinary oncology at Sloan-Kettering. "The key is to analyze your own results and improve your own skills and surgical techniques. It is clear that we can all become more skilled surgeons."