ProtecT trial results add more grist to the PSA screening mill

Chris Booth, a member of Tackle's Clinical Advisory Board, has been studying the results of the ProtectT trial and observes as follows:

Despite major advances in treatment over the 10 year course of this study, the death rate from prostate cancer (PCa) in the UK remains at a highly unsatisfactory 11,000 each year.

Over this time men with early stage, non-aggressive PCa and more than 10 years’ life expectancy have routinely been offered active surveillance as an alternative to radical surgery or radiotherapy.  This trial has confirmed the safety of active surveillance.

Does the trial prove anything else or suggest changes in future practiceUndoubtedly!

All the men in the trial had PSA screening detected cancers.  Over half initially on surveillance showed signs of progression and switched to radical treatment.  Presumably, without screening in the first place, these men would have presented with late stage, incurable disease and most likely added to our PCa death toll. This progression rate is not surprising given the limitations on the accuracy of standard TRUS biopsies during the trial period 1999-2009.  However, the results of the PROMIS trial of multiparametric MRI (mpMRI) now offers the hope of early recognition of significant cancer likely to progress whilst saving those with insignificant, non-aggressive cancers even the need for invasive biopsies;  a major reduction in “over-diagnosis”.  However, none of these benefits applies without PSA screening in the first place.

Does the trial have implications for PSA-based screeningObviously!

Only 8% of eligible UK men undergo PSA screening compared with 60% in most Western countries.  This alone probably contributes most to our high death rate.  PROMIS and ProtecT now confirm that current UK clinical practice has both the tools and the method to avoid the twin bogies of screening – “over-diagnosis” and “over-treatment”.

Given that organised screening trials in Europe are delivering a 40-50% drop in mortality from PCa, we should surely now put our efforts into increasing our lamentable screening rate if we are to reduce our death rate.  Indeed, with all the main urological associations worldwide supporting appropriate PSA-based screening and in the face of all this new evidence, it is simply not good enough for Dr Anne Mackie of the UK National Screening Committee to continue to trot out the mantra that PSA screening in the UK today “would do more harm than good”.  Where is the proof of that against all this new evidence?