Prostate cancer screening occurs in many countries ahead of evidence from ongoing trials. In many countries, early detection (including the UK, when practised), and opportunistic screening commences at 50 years, but a lower age limit has recently been adopted in the USA based on two studies that found elevated prostate specific antigen (PSA) levels in men in their 40s was associated with subsequent prostate cancer.
So a team of UK researchers set out to investigate the feasibility of prostate cancer testing, disease prevalence and characteristics in a random group of younger men. Their findings are published on bmj.com.
The study involved 473 men aged 45-49 years randomly selected from eight general practices in one UK city.
Of 442 men (34%) who agreed to PSA testing, 54 (12%) had an elevated PSA result. These men were invited for further testing (an ultrasound-guided prostate biopsy, a repeat PSA test, and a digital rectal examination).
Ten prostate cancers were detected (a 2.3% detection rate, similar to that in older men). The five men whose tumours were potentially risky to health agreed to have one of three treatment options (radiotherapy, surgery, or active monitoring).
This study shows that men younger than 50 years will accept prostate cancer testing, but at a much lower rate than older men, say the authors, so if screening were introduced, greater efforts would be needed to maximize uptake in this age group.
If the UK male population aged 45-49 years (2,236,000) were to undergo PSA screening they estimate that 272,905 men would have a raised PSA and of these 51,449 would have prostate cancer.
Some of these cancers may benefit from treatment, they say, but this has to be set against the likely distress caused to the 221,456 men with negative biopsy results and the risks of over-treatment and associated side-effects to those diagnosed with cancer.
This study will inform the debate about PSA thresholds and age limits only if prostate cancer screening is proven to be effective in ongoing trials, they conclude.
Until the results from ongoing trials are available, policy should advocate informed discussion between clinicians and patients about the benefits, potential harms, and limitations of prostate cancer screening, says an accompanying editorial.