WHY IS TESTING DIFFICULT?

SCREENING for breast cancer is routine, but tests for prostate cancer are more haphazard, with accurate tools only just beginning to emerge.

The breast screening programme, which offers mammograms to all women aged 50-70, is credited with saving 1,400 lives by flagging the cancer before it spreads.

But there is no national prostate screening programme as for years the tests have been too inaccurate. Doctors struggle to distinguish between aggressive and less serious tumours, making it hard to decide on treatment.

Men over 50 are eligible for a ‘PSA’ blood test which gives doctors a rough idea of whether a patient is at risk. But it is unreliable. Patients who get a positive result are usually given a biopsy, which is also not foolproof.

A major trial last year showed MRI scans were more accurate than biopsies, but only half of hospitals have the right equipment. The NHS is beginning to use MRI scanners, but this is not yet routine, and still relies on patients having a PSA test or symptoms first.

A team at UCL is embarking on a trial of MRI without PSA or symptoms, but the research is at an early stage and it will be several years until results are produced.

The lack of an accurate test means many men undergo treatment they do not need. Currently, 20,000 men with localised prostate cancer have unnecessary radiotherapy or surgery each year.