London, Jan 20 (IANS): Giving men, suspected of having prostate cancer, an MRI scan may improve diagnosis and save those who do not have aggressive cancers from having an unnecessary biopsy, researchers have shown.

According to the study, published in The Lancet, adding an extra multi-parametric MRI (MP-MRI) scan may help one in four or 27 per cent men avoid an unnecessary biopsy and reduce by five per cent the number of men who are diagnosed with a cancer.

"Prostate cancer has aggressive and harmless forms. Our current biopsy test can be inaccurate because the tissue samples are taken at random. This means it cannot confirm whether a cancer is aggressive or not and can miss aggressive cancers that are actually there," said lead author Hashim Ahmed from University College London.

As a result, some men with no cancer or harmless cancers are sometimes given the wrong diagnosis and are then treated even though this offers no survival benefit and can often cause side effects.

"On top of these errors in diagnosis, the current biopsy test can cause side effects such as bleeding, pain and serious infections," Ahmed added.

Multi-parametric MRI (MP-MRI) scans, which provide information about the cancer's size, how densely packed its cells are and how well connected to the bloodstream it is, could help differentiate between aggressive and harmless cancers, the researchers said.

However, "biopsies will still be needed if an MP-MRI scan shows suspected cancer too, but the scan could help to guide the biopsy so that fewer and better biopsies are taken," Ahmed noted.

For the study, 576 men with suspected prostate cancer were given an MP-MRI scan followed by two types of biopsy.

Of these, the MP-MRI scan correctly diagnosed almost all of the aggressive cancers (93 per cent), whereas the biopsy correctly diagnosed only half (48 per cent).