We can't afford to skimp on screening

This month is prostate cancer awareness month, a disease made more prominent by sufferers such as Andrew Lloyd Webber.

My message is always the same: be aware of the risks and any changes, check for lumps and bumps and go and see your GP. But a new survey by The Prostate Cancer Charity has shown that a fifth of men who asked their GP for a prostate cancer test were refused one, and that these were men from at-risk groups too.

On the face of it, this is a worrying development but, as is often the case, it's not as clear-cut as it first seems. Prostate screening is not simple, and GPs must be allowed to make decisions on likely risk, based on their training and experience — not on laboratory-generated numbers.

This is because the test measures prostate-specific antigen (PSA), produced by the prostate, but PSA levels alone do not distinguish benign prostate conditions from cancerous ones. Although they can help us GPs decide whether to investigate further or not.

In general, a higher PSA level can be an indicator of problems. However, not every man with an elevated PSA will have the disease; only 25 to 35 per cent of men who are given a biopsy as a result of an elevated PSA will actually have prostate cancer.

So PSA testing does require a certain amount of careful explanation — another reason why some GPs are not offering it — and its complexity is a valid argument against screening.

I suspect, however, that many GPs are making their decision based purely on cost. Which is a great shame because men — traditionally reluctant to discuss their health problems — are being turned away just when they have plucked up courage to seek help. If they were given a good explanation as to why the test was not appropriate for them they might be appeased. But I fear many don't get this and will never ask again.