Presentation Authors: David Thurtle, Cambridge, United Kingdom, Valerie Jenkins, Brighton, United Kingdom, Paul Pharoah, Vincent Gnanapragasam*, Cambridge, United Kingdom
Introduction: Decision-making around treatment for non-metastatic prostate cancer (PCa) is notoriously complex. Treatment counselling is performed by clinicians with different perceptions on disease lethality and hence biased opinions on the value of radical treatment. In this study we assessed clinician understanding of prognosis in PCa, comparing responses to the multivariable prognostic model PREDICT Prostate - derived from high quality survival data and validated in 3 PCa cohorts (including >80,000 men). We then reviewed current treatment practices, and assessed what impact PREDICT Prostate would have on these.
Methods: Study materials were managed using Qualtrics research software (Utah, USA). Participation of PCa specialists was requested predominantly through professional mailing lists. Respondents were randomised into group A or B and presented with opposing hypothetical vignettes: 6 with clinical diagnostic information only and 6 with these details plus PREDICT Prostate estimates. Comparisons were made between groups for clinician-estimated and model-predicted 15-year outcomes. Data analyses were performed using Stata 14 (Texas, USA).
Results: 190 responses were received. 63.7% and 16.8% of respondents were urologists and oncologists respectively. 59.5% work in specialist cancer centres and 81.6% counsel men with PCa at least weekly. Only 19.3% reported using any survival prediction tool in their current routine practice. Clinician estimates of 15-year prostate cancer mortality (PCM) 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 likelihood of recommending radical treatment in 9/12 (75%) vignettes, with reductions most evident in intermediate-risk cases. For example, in a fit 75-year old man with PSA 5.1, Gleason 3+4 PCa 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).
Conclusions: Our study suggests clinicians consistently overestimate PCM and the survival benefits of radical treatment. PREDICT Prostate can provide individualised and contextualised prognostic information to help standardise therapy recommendations.
Source of Funding: The Urology Foundation (UK Charity)