Prostate cancer screening: Have we tipped the seesaw?

Abstract

43 Background: Screening for prostate cancer has been and remains contentious with evidence of harms and benefits finely balanced and inadequate to tip the see saw one way or another in order to give men clear, understandable guidance on PSA testing. In recent years the diagnostic pathway has changed significantly delivering a modern pathway that is likely to do far less harm and possibly more benefit. Our work quantifies the levels of harm and benefit at each stage of the entire pathway currently used in the UK from initial PSA through to biopsy-confirmed diagnosis of prostate cancer. Methods: Combining the full results of the most recent high quality diagnosis clinical trials, as well as real world evidence and practice patterns we have mapped each stage of the UK diagnostic pathway. Through this research we are able to quantify the number of men benefitting (i.e. those who move through the pathway correctly with an eventual diagnosis of clinically significant prostate cancer) and the number of men suffering harm (those who suffer biopsy side effects or who are subjected to unnecessary testing as they move through the pathway with no clinically significant cancer). Results: Initial results using clinical trial data and current practice patterns in the UK indicate that 10,000 men entering the diagnostic pathway with a PSA test would generate the following results. Diagnostic outcomes: 463 men would be diagnosed with a clinically significant (Gleason 3+4 or above) localised prostate cancer; 110 men would be diagnosed with a clinically insignificant (Gleason 3+3) prostate cancer; and 646 men would be taken through the entire diagnostic pathway with no diagnosis of prostate cancer. Harm: a maximum of 38 men would suffer clinical side effects from their biopsy. Healthcare costs: 10,000 PSA tests, 1,449 multiparametric MRI scans, and 1,207 biopsies would yield 463 significant cancers diagnosed. An estimated 1,258 clinically insignificant and 168 clinically significant cancers would remain undiagnosed using the current diagnostic pathway due to initial PSA below 3ng/ml. Conclusions: Rates of biopsy-related harm in modern practice are encouragingly low and likely to reduce further. A PSA-initiated diagnostic pathway misses a significant proportion of clinically important cancers. It is interesting to note the high conversion from MRI to biopsy in the data underpinning this model. Next steps will include analysis of the same outcomes in several centres in the UK to determine if actual practice matches expected outcomes (harms and benefits) from previous clinical trials.