For this study, the participation of prostate cancer specialists was requested predominantly through professional mailing lists. Respondents were randomized into group A or B and presented with opposing hypothetical vignettes: (i) 6 with clinical diagnostic information only and (ii) 6 with these details plus PREDICT Prostate estimates.
Comparisons were made between groups for clinician-estimated and model-predicted 15-year outcomes.
There were 190 responses received, of which 63% were urologists and 17% were oncologists. Furthermore, 60% of respondents work in specialist cancer centers and 82% counsel men with prostate cancer at least weekly. Interestingly, only 19.3% reported using any survival prediction tool in their current routine practice. Clinician estimates of 15-year prostate cancer mortality exceeded PREDICT Prostate estimates in 92% of the case vignettes; clinicians estimated 1.9-fold greater disease lethality than PREDICT. Clinician perceptions of overall survival benefit from radical treatment at 15 years were over-optimistic in every vignette, with mean clinician estimates 5.4-fold greater than PREDICT. Concomitantly viewing data from PREDICT Prostate led to reductions in the likelihood of recommending radical treatment in 75% of vignettes, with reductions most evident in intermediate-risk cases. Dr. Gnanapragasam notes for example, in a fit 75-year old man with PSA 5.1, Gleason 3+4 prostate cancer in 2/12 biopsy cores: likelihood of recommending treatment dropped from 32.5% to 19.1% when PREDICT estimates were also shown (p=0.009).
This is an important study and results may help with appropriately managing patients considering active surveillance for appropriate risk of prostate cancer. Dr. Gnanapragasam concluded with several summary points:
- Clinicians tend to overestimate prostate cancer lethality and the benefits of radical treatment
- Significant variation in baseline estimation of lethality and the benefits gained from treatment
- A standardized individual prognostic model may help inform true relative survival benefits and reduce treatment recommendation variation.
Presented by: Vincent Gnanapragasam, University of Cambridge, Cambridge, United Kingdom
Written by: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University - Medical College of Georgia, @zklaassen_md at American Urological Association's 2019 Annual Meeting (AUA 2019), May 3 – 6, 2019 in Chicago, Illinois