David F. Friedlander MD MPH - Renal and Urology News

Ask the Experts – David F. Friedlander, MD, MPH

Expert Perspective
Facility-Level Variation in Use of Pelvic Lymphadenectomy in High-Risk Prostate Cancer
David Friedlander MD

David F. Friedlander, MD, MPH

Practice Community: San Diego, California

Hospital and Institutional Affiliations: Associate Physician and Urology Fellow, University of California San Diego

Practice Niche: Endourology and minimally invasive urologic surgery

Dr Friedlander is the first author of a study published online December 17, 2019 in the Annals of Surgical Oncology1 that examined facility-level variation in the performance of pelvic lymphadenectomy during radical prostatectomy for high-risk prostate cancer and its effect on overall survival. The study, which included 13,652 men, is distinguished by its examination of the extent of lymphadenectomy by category rather than as a continuous variable: no/limited, standard, and extended (0-9, 10-16, and 17 or more lymph nodes, respectively).Risk-adjusted facility-level predicted probabilities of no/limited, standard, and extended lymphadenectomy ranged from 0.01%-52.6%, 3.3%-53.3%, and 17.8%-96.3%, respectively.

Question 1. What prompted the study?
Answer
It is an interest of mine and senior author Dr Quoc-Dien Trinh [of Brigham and Women’s Hospital and Harvard Medical School in Boston] to help improve standardization of surgical practices. We observed that there seemed to be quite a bit of variability with regard to when and to what extent pelvic lymph node dissection is performed following radical prostatectomy.
Question 2. What were your major findings?
Answer
The most important finding was the wide variation among facilities of undergoing different types of lymph node dissection. Our follow-up could have been longer, ideally, but, at the end of the day, we did find that despite this variation, there really is no difference in overall survival with different extents of pelvic lymph node dissection.
Question 3. Were you surprised by the findings?
Answer
I was very shocked by the extent of facility-level variation; one would assume that it wouldn’t be as marked as we observed. With regard to the survival benefit, I wasn’t terribly surprised. I don’t think there’s a lot of literature suggesting that there is a survival benefit associated with extensive pelvic lymph node dissection during radical prostatectomy. The consensus is that it’s certainly very helpful for staging purposes, but I have yet to see a robust study suggesting an associated survival benefit.
Question 4. To what would you attribute the wide facility-level variation in the extent of lymphadenectomy?
Answer
Guidelines recommend that pelvic lymph node dissection be performed in the setting of intermediate- and high-risk prostate cancer. At academic medical centers and tertiary referral centers, you tend to have, for example, greater interdisciplinary collaboration, you may have tumor boards, and the presence of multiple specialties. As a result, specialists may be able to collaborate with one another, either preoperatively or postoperatively, and discuss contemporary literature guiding clinical and surgical practice, including the performance of pelvic lymphadenectomy.
Question 5. What are the potential clinical implications of your findings?
Answer
Obviously there are limitations with regard to the survival data. With that being said, it certainly supports prior literature suggesting there is no survival benefit associated with more extensive pelvic lymph node dissection. There is significant variation with regard to clinical and surgical practices. As we move toward value-based care and potential penalties for not delivering standard of care, it’s going to be critically important that we appraise variations in practices and the sources of that variation so that we can greater standardize it. It’s really important not to just think about standardization of practice, but also standardization of how we define these practices. Our data may help inform that.
Question 6. Your study cohort included patients diagnosed with prostate cancer from 2004 to 2011. Advances in imaging techniques (such as PSMA PET/CT) have been made that could allow for more accurate preoperative nodal staging. Would greater accuracy in predicting the presence or absence of nodal metastases decrease facility-level variation?
Answer
Hard to say. We observed differences between academic and comprehensive community practices. It is reasonable to infer that some of the factors influencing the difference in facility-level variation in pelvic lymphadenectomy also likely affect rates of preoperative imaging. So I suspect that certain facilities would be earlier adopters of advanced imaging technology, whereas others, for example, community centers, might not adopt that technology. Therefore, you wouldn’t necessarily see a difference in facility-level variation.
Question 7. Overall, do you think your findings would be the same if you looked at a more recent cohort?
Answer
Rapid adoption of PSA screening led to a pathologic stage migration in prostate cancer. In the era of active surveillance and controversy surrounding PSA-based screening, it’s now conceivable that we’re seeing a greater incidence of men diagnosed with intermediate- or high-risk prostate cancer, so it’s possible that overall we would observe a greater number and greater prevalence of pelvic lymphadenectomy simply because of that stage migration.

Reference

  1. Friedlander DF, Krimphove MJ, Cole AP, et al. Facility-level variation in pelvic lymphadenectomy during radical prostatectomy and effect on overall survival in men with high-risk prostate cancer. Ann Surg Oncol. 2019. doi: 10.1245/s10434-019-08110-3