Source: Thailand Medical News Dec 21, 2019 5 years, 5 days, 4 hours, 59 minutes ago
Prostate Cancer
According to a new University College of London-led computer modelling study, nearly one in six deaths from
prostate cancer could be prevented if targeted
screening was introduced for men at a higher genetic risk of the disease.
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Prostate cancer is the most common form of
cancer in
men with around 1.3 million new cases diagnosed globally each year and more than 400,000
men a year dying as a result of the disease. However, unlike breast and cervical cancer there is currently no national
screening programme for this disease in most countries.
Typically, a blood test that detects raised levels of the
prostate-specific antigen (PSA) can be used to screen for
prostate cancer. However, this test is not a reliable indicator as it does not accurately distinguish between dangerous
cancers from harmless ones,leading to both unnecessary operations and missed
cancers that are harmful.
The new study, published in
PLOS Medicine, modelled the harms and benefits of introducing four-yearly PSA screening for all
men aged 55 to 69 versus more targeted checks for those at higher risk of the disease.
The medical researchers concluded that the best approach would be to screen
men at a slightly higher genetic risk, nearly half of
men in that age group as this would have the biggest health benefit, preventing deaths from
prostate cancer while minimising unnecessary treatments for harmless tumours. This is because
men with a higher genetic risk are more likely to benefit and less likely to be harmed by undertaking screening.
"
Prostate cancer is a leading cause of
death
from
cancer in
men in the UK, but screening is not performed because the harm of overdiagnosis is thought to outweigh the benefits. Our study shows that targeted
screening can reduce unnecessary diagnoses while helping to prevent people dying from the disease by enabling earlier detection." commented Professor Dr Nora Pashayan (UCL Applied Health Research), senior author of the study, during a phone interview with
Thailand Medical News.
The researchers created a hypothetical cohort of 4.5 million
men, representing the number of
men aged 55 to 69 in England, and simulated the outcomes of introducing
screening into this population. Outcomes including
prostate cancer deaths averted, unnecessary diagnoses and
screening costs were compared for no
screening, universal age-based
screening and more
targeted
screening using a range of thresholds of genetic risk.
The best optimal scenario, the researchers concluded, would be to
screen men with a 4-7% risk of getting
prostate cancer over the next 10 years,that is, between roughly half and a quarter of all
men aged 55 to 69.
Medical screening all
men in that age group would result in the most deaths averted (20%) but, along with the extra cost, would also lead to a large number of unnecessary diagnoses, with nearly one in three
cancers detected by screening being harmless.
It was showed that screening at a threshold of 4% would prevent 15% of deaths from
prostate cancer, nearly one in six deaths while delivering the greatest gains in terms of quality adjusted life years, meaning more years of good health across the population. This would also reduce the number of unnecessary diagnoses of harmless
cancers by about one third compared with screening all
men aged 55 to 69.
Medically
screening men with a 4-7% risk would also be much more cost effective than
screening all
men aged 55 to 69, saving between a fifth (for the 4% risk threshold) to nearly half of the cost (7% risk threshold), while maintaining the benefits of
screening.
With the scenarios simulated,
men aged 55 to 69 would have four-yearly checks once they had reached the risk threshold. This would mean a widening proportion of
men having checks the older they got, as older
men are at greater risk of the disease.
New pioneering UCL-led research has already led to a change in the way
prostate cancer is diagnosed. As of last December, MRI is now recommended as the first test for
men suspected of having the
cancer, after two clinical trials conducted with University College London Hospitals (UCLH) trust found MRI scans could markedly and safely reduce the numbers of
men needing an invasive biopsy.
"I feel we now have the tools that help us identify
men with clinically important disease applying these tools to the right patient has to be the future. That is why this work is so important in helping us know who and when to
screen." said Professor Mark Emberton (UCL Medical Sciences).
The researchers said targeted
screening based on genetic risk would require an evolution of
screening services. They noted that inviting people for
screening at different ages may affect
screening delivery and that the broader impact of
screening using genetic risk required further research.
Reference : Tom Callender, Mark Emberton, Steve Morris, Ros Eeles, Zsofia Kote-Jarai, Paul DP Pharoah, Nora Pashayan, 'Polygenic Risk-Tailored Screening for Prostate Cancer: A Benefit-Harm and Cost- Effectiveness Modelling Study' PLOS Medicine (2019). DOI: 10.1371/journal.pmed.1002998
