Paul McNamara is a Principal GP in Glasgow and honorary clinical lecturer at the University of Glasgow
Scott Wylie is a final year medical student at the University of Glasgow
“To me, it seems a no-brainer – why would they not bring the age down and just allow more men to go in and get a blood test?” – Sir Chris Hoy1
In October 2024, 48-year-old cyclist Sir Chris Hoy publicly announced his diagnosis of stage IV prostate cancer. Only recently surpassed as Scotland’s most decorated Olympian, Hoy is best known as an icon of the London 2012 games and as a formidable, powerful, and determined athlete. His young age and public perception of his fitness induced a shock response to the diagnosis; perhaps more thought provoking, however, was his serene and philosophical perspective as he conveyed his gratitude for every day of life since ‘nobody lives forever’.1
Nevertheless, one could hypothesise that the narrative would be altogether quite different had his disease been detected earlier, before it reached a palliative stage. Judging by the epigraph, Hoy perhaps agrees – his announcement is not merely a reflective musing on stage IV cancer but a rousing advocation for early detection. Predictably, the debate around asymptomatic prostate cancer screening has again been thrust into the public sphere.
…men with a positive family history are two and half times more likely to develop prostate cancer than men who do not, and their risk of early-onset cancer, before their post-50 PSA test, is similarly elevated.
There is of course no nationwide prostate cancer screening programme for asymptomatic men at present; rather, men over the age of 50 are advised that they can request a prostate-specific antigen (PSA) test from their GP at any time.2 Hoy reasons that a ‘surge’ of asymptomatic younger men requesting a PSA test, especially those with a family history of prostate cancer, may put pressure on policy makers to alter the current screening guidelines.1 This reasoning holds up on multiple fronts. Firstly, men with a positive family history are two and half times more likely to develop prostate cancer than men who do not, and their risk of early-onset cancer, before their post-50 PSA test, is similarly elevated.3 Secondly, the incidence of early-onset cancers is known to be escalating – between 1990 and 2019, the incidence of early-onset cancer diagnoses increased by 79.1% globally with prostate cancer (alongside nasopharyngeal cancer) showing the sharpest increase.4 Similarly, between 1993 and 2018, cancer diagnoses in UK males aged between 35 and 69 rose by 57% – an increase driven by early prostate cancer diagnoses specifically.5 In the UK, as all-cancer incidence has increased in this group, mortality has inversely declined, a phenomenon is driven by lifestyle factors, developments in treatment, and, perhaps most importantly, early detection.5
Given the upsurge in the incidence of early-onset cancer generally and early-onset prostate cancer specifically, perhaps it is indeed logical to reconsider diagnosis and screening to account for the evidential demographic shift. Such re-evaluation is not restricted to the context of nationwide asymptomatic screening but extends to risk assessment in individual cases in general practice – the publicity garnered by Hoy’s case has perhaps already affected GP’s cognitive bias. The glaring issue, however, is of course the screening test itself – while PSA may be raised in prostate cancer, results are far from clear-cut.
Overdiagnosis in this case describes the diagnosis of an asymptomatic person despite their ‘disease’ never causing future health problems; it describes ‘making people patients unnecessarily’.
Issues of PSA’s poor specificity, and to a lesser extent sensitivity, are well-known and the test may be thought of proverbially as ‘opening the flood gates’ to a myriad of causes other than treatment-worthy malignancy. Research endeavouring to analyse the ‘efficacy and safety’ of PSA to screen for prostate cancer has frequently concluded that such screening would be ultimately futile.6 Although screening with PSA may improve detection of any-stage prostate cancer, there would be negligible impact on ‘disease-specific mortality’ and no impact on ‘overall mortality’.6 Furthermore, while PSA screening would likely be non-beneficent, it could in fact prove harmful due to a high risk of overdiagnosis.6 Overdiagnosis in this case describes the diagnosis of an asymptomatic person despite their ‘disease’ never causing future health problems; it describes ‘making people patients unnecessarily’.7 The figures discussed previously regarding increasing cancer rates are thought to be skewed by overdiagnosis through PSA testing.5 For the ‘patient’, the consequences include the physical and psychological burdens of unnecessarily investigating and treating an indolent condition7. Hoy himself described the psychological impact of his investigations as a ‘waking nightmare’.1 It could be argued that, due to PSA testing’s propensity for overdiagnosis, asymptomatic screening could induce a similar ordeal in men who need not have been labelled with a cancer diagnosis in the first place, as well as having social ramifications including patients’ future insurability.
Time will tell what the renewed public interest in and debate around early onset prostate cancer will mean. Perhaps we will see change in screening policy and hopefully a drive to continue research for more accurate biomarkers, genetic testing, and diagnostic imaging. It must be noted that increased screening, and further investigation of positive results, would have massive implications for workload in an NHS that is already stretched beyond capacity. Nevertheless, Hoy has drawn important public, and professional, awareness towards the groups most at risk of early onset prostate cancer – black men and those with a positive family history.8 PSA testing should, however, be used responsibly with an awareness of the implications of its results.
References
1. Hoy C. Interviewed by: Nugent S. BBC. 5th November 2024
2. NHS. Overview: Prostate Cancer. https://www.nhs.uk/conditions/prostate-cancer/ [Accessed 8th November 2024]
3. Johns L, Houlston R. A systematic review and meta-analysis of familial prostate cancer risk. BJU International. 2003;91(9):789-94 https://pubmed.ncbi.nlm.nih.gov/12780833/
4. Zhao J (et al). Global trends in incidence, death, burden and risk factors of early-onset cancer from 1990 to 2019. BMJ Oncology. 2023;2(1):e000049 https://bmjoncology.bmj.com/content/2/1/e000049#ref-2
5. Shelton J (et al). 25 year trends in cancer incidence and mortality among adults aged 35-69 years in the UK, 1993-2018: retrospective secondary analysis. BMJ. 2024;384:e076962 https://www.bmj.com/content/384/bmj-2023-076962
6. Ilic D (et al). Prostate cancer screening with prostate-specific antigen (PSA) test: a systematic review and meta-analysis. BMJ. 2018;362:k3519 https://www.bmj.com/content/362/bmj.k3519
7. Brodersen J (et al). Overdiagnosis: what it is and what it isn’t. BMJ Evidence-Based Medicine. 2018;23:1-3. https://ebm.bmj.com/content/23/1/1
8. Hussein S (et al). Young-age prostate cancer. BMJ Journal of Clinical Pathology. 2015;68:511-515 https://jcp.bmj.com/content/68/7/511
Featured image by Karsten Winegeart on Unsplash
