by David Cameron is the latest high-profile figure to back growing calls for the NHS to start screening men, or at least those at highest risk, for prostate cancer after they themselves have been treated for it.
He joined Olympic cycling champion Chris Hoy and prostate cancer charities in saying recent advances in diagnosing the disease mean tests can be introduced that are much safer than traditional methods, which can produce both false positive and false negative results.
However, others, including Cancer Research UK, disagree.
The UK National Screening Committee will meet on Thursday to discuss the latest evidence on the issue. The independent committee advising ministers is under pressure to allow testing to begin on the men at highest risk: black men, those with a family history of prostate, breast or cervical cancer, and men who carry the BRCA1 or BRCA2 gene.
What is prostate cancer, what are its symptoms and which groups are most at risk?
Prostate cancer arises in the prostate.
With around 55,300 new diagnoses and 12,200 deaths each year, it is the second most common cancer in the UK after breast cancer. It is the most common type of cancer in men. Almost 80% of men diagnosed with it survive at least 10 years.
In the early stages there are often no symptoms. But changes in men’s urinary habits – such as needing to pee more often, even overnight – can be a clue, as can erectile dysfunction.
Men over 50 are particularly affected. However, three groups of men are most at risk: black men; Individuals with a family history of prostate cancer or breast or ovarian cancer in female relatives; and men who are carriers of the BRCA1 or BRCA2 gene variants.
Black men are twice as likely to get it and die from it. A quarter of black men will be diagnosed with prostate cancer during their lifetime, compared to one-eighth of the general male population.
Black men in England are also more likely to be diagnosed with late-stage prostate cancer than their white counterparts. Socioeconomic circumstances and genetic factors are believed to contribute to the risk increasing significantly.
How is prostate cancer detected?
All men over 50 can request a PSA test to determine whether they have prostate cancer. These men and those in higher risk groups can speak to their primary care doctor about the pros and cons of getting tested.
GPs no longer need to assess a man’s prostate through a rectal exam. Men at higher risk have historically been offered a biopsy, in which a needle is inserted into their prostate.
A PSA test checks the level of prostate-specific antigen (PSA) in the blood. Other medical conditions can cause elevated PSA levels, including an enlarged prostate and prostatitis, not just prostate cancer.
Unlike smear tests for cervical cancer and mammograms for breast cancer, the PSA test is not, per se, a test for prostate cancer. It’s useful but not definitive.
Although any man can ask their GP for a test and they will usually refer anyone over 50 who requests a test, the NHS does not offer routine PSA testing. This is because blanket PSA testing could lead to overdiagnosis of prostate cancer and result in men undergoing unnecessary biopsies and invasive treatments, including surgical removal of the prostate.
For example, some studies have shown that black men may have higher PSA levels than their white counterparts and that using the PSA test in men without prostate symptoms does not reduce prostate cancer deaths.
Why doesn’t the NHS screen men for prostate cancer?
In the UK, people are routinely screened for breast, bowel and cervical cancer, but not for prostate cancer, even though it is common.
Because of the historical weaknesses of the PSA test – the likelihood of both false positives and false negatives – and the historical lack of alternative screening methods, screening for it is not as easy as for other cancers.
Britain’s National Screening Committee (NSC), independent experts who advise ministers, is due to decide on Thursday whether the NHS should start screening for the disease either all men or those in some or all three of the higher risk groups.
In recent months it has been under intense pressure to reconsider its position on screening. It spent months collecting and analyzing evidence.
Charities such as Prostate Cancer UK and Prostate Cancer Research say the NSC should at least authorize targeted screening of men in the three higher-risk groups. This would uncover more cases and therefore save more lives, they say.
Lithuania (2006), Kazakhstan (2013) and Sweden (2020) have already introduced screening for many or all male citizens aged 50 or over.
What arguments speak for and against targeted prostate cancer prevention?
Prostate cancer researchers insist that recent advances in diagnostic testing mean screening could be introduced with far lower risks than those of the PSA test.
Men could be screened safely using a PSA test, followed by a pre-biopsy MRI scan – “which rules out cancer in a large proportion of cases” – and then, if necessary, a transperineal biopsy, sparing many of them the rigors and risks of a traditional biopsy.
“The central security objection to screening has basically been worked out of the system,” it says.
Prostate Cancer UK agrees. “We believe the evidence shows that screening men at highest risk is safe and more beneficial than the harm that could result from the screening program,” says Chiara De Biase, director of health services, equity and improvement.
“MRI before biopsy improves the detection of clinically significant prostate cancer and reduces the risk of diagnosing cancers that do not require treatment. We hope the committee agrees and urgently await the outcome,” the charity says.
However, others, notably Cancer Research UK, claim there is still too much “conflicting evidence” around screening to justify even a targeted program. “The evidence for targeted screening is still very unclear,” says Naser Turabi from CRUK.
What might a prostate cancer screening program look like?
The TRANSFORM prostate cancer screening trial may provide the answer. The £42 million study is the largest and most ambitious study of prostate cancer screening in 20 years.
The aim is to find the most effective and least harmful methods to screen the adult male population in the UK and detect the disease in its early stages. 300,000 men are recruited for the process.
It is led by Prostate Cancer UK and is due to report in 2027. The NSC has agreed to re-examine prostate cancer screening in light of the TRANSFORM results. The National Institute for Health and Care Research is covering £16m of the £42m cost.
The study will also examine how current testing methods, including PSA blood tests, genetic spit tests and MRI scans, can be used more effectively in early detection of the disease.
Dr. Sam Merriel, from the Center for Primary Care and Health Services Research at the University of Manchester, said: “Better evidence using modern approaches to prostate cancer screening, incorporating the latest tests, including prostate MRI and genetic testing, is urgently needed to find better ways to screen for prostate cancer than relying on PSA alone.”
