By Michelle Roberts
BBC News Online health staff
Prostate cancer is now the most common form of cancer in UK men, but there is considerable debate over whether men should be routinely screened for this disease.
Scanning helps guide biopsy
Although the government does not run a national screening programme, men can request testing. But should they?
Experts' views are mixed.
Prostate cancer, the second most common cause of cancer-related death in UK men, is treatable, but the disease can be advanced before the man gets any symptoms.
The prostate specific antigen (PSA) test can help doctors decide whether prostate cancer is likely, but it is not foolproof.
Some men with prostate cancer do not have a raised PSA and some men with a raised PSA do not have prostate cancer.
For every 100 men with a raised PSA, only about a third will have any cancer cells in their prostate.
If PSA is raised, the man will need a biopsy of their prostate - a needle which extracts cells from the gland - to diagnose the problem. Biopsy can be painful and cancers can still be missed.
Even if cancer is present, a man may die with it rather than from it.
By the age of 80, about 50% of men will have prostate cancer but only 4% will ultimately die of the disease as a result.
Also, the treatments available have significant side-effects, including impotence, incontinence and psychological stress.
And there is no consensus as to the best treatment. A project is running for the next 10-15 years in the UK to work out whether it is best to treat men with prostate cancer with surgery or radiotherapy or simply to monitor them.
Researchers also disagree about whether interventions actually save lives.
Pros and Cons
The NHS's screening committee advises against PSA testing for men with no symptoms who are unlikely to live for longer than 10 years.
Men can get a PSA test from their GP if they wish to after all of the pros and cons have been discussed with them.
Despite this, private health companies like BUPA routinely offer PSA testing to men over the age of 50 as part of "wellman" checks (BUPA Wellness Classic, Premier or Later Life Health Assessment).
Reasons for an increased PSA
A benign prostate growth (BPH)
Ejaculating in the past 48 hours
Vigorous exercise such as riding a bike in the past 48 hours
Prostate biopsy in the past six months
A digital rectal examination in the past week
Dr Peter Mace, clinical director of BUPA Wellness, said:
"Before offering men routine screening for prostate cancer (PSA), we ensure that they are informed of the pros and cons of testing. Ninety per cent of them have the test.
"Where we find an illness, people are very grateful that it has been caught early. Where nothing is found, people are relieved.
"The majority of our health assessment clients have private medical insurance which covers the cost of follow-up tests or treatment.
"We believe that regular health screening is a valuable contributor to people's knowledge of their own health."
A survey by the Prostate Cancer Charity found two-thirds of 150 male GPs would not bother to have a PSA test.
Dr Chris Hiley, head of policy and research at the Prostate Cancer Charity, said: "We believe all men need to know that PSA testing is available from their GP, but that it is not yet clear if lives are saved by the test.
"Men need to be fully informed of the risks and benefits of this type of testing."
Knowledge better than ignorance
Mr Neil O'Donoghue, consultant urologist at University College London, said it was more debatable what to do when the test is positive rather than whether to do the PSA test itself.
"Ignorance is not always bliss in relation to PSA.
"If a man asked me whether he should have a PSA test, I would say he should have it. It's always better to have information. You don't have to do anything about it.
"You still have to take decisions if someone has an elevated PSA. The first is 'Are they going to go for a biopsy?' and the second is 'If the biopsy is positive, what sort of treatment should we offer them?'
He said the best treatment depended on many factors, such as the patient's age and the aggressiveness of the cancer.
He thinks men with a life expectancy of less than 10 years should be offered and could benefit from screening and treatment.
Peter Baker from the Men's Health Forum said: "We are not in a position where we can say men should have a PSA test when they have no symptoms.
"We do not have the evidence yet to say that lives would be saved. We do not know which the best treatment is and if it saves lives.
"I certainly would not advise someone to rush off and have a PSA test. Talk to your doctor."
He said men who are at greater risk of prostate cancer - those with a family history of prostate cancer, whose father or brother had it, and men of Afro-Caribbean descent - should think about it more actively than other men.
Private health checks could be very expensive and that men should be encouraged to get simple health checks for free through the NHS, he added.
"If there's one check that every man should have routinely its blood pressure because blood pressure produces no symptoms but it's a killer," he said.