Men with prostate cancer are being given false hope by tests that underestimate the aggressiveness of their disease, a study suggests.
Researchers found that more than half of a group of men whose cancers were initially classified as slow-growing and confined turned out to have more dangerous tumours.
The findings, published in the British Journal Of Cancer, call into question the ability of experts to grade and stage prostate cancers on the basis of biopsy samples.
It also casts doubt on the "active surveillance" strategy of avoiding unnecessary radical treatment for patients with slow-growing prostate cancer.
Instead, these patients are often closely monitored but left alone until tests suggest their condition has worsened.
More top news
Rain will be heavy across Scotland, parts of northern England and Wales tonight - rumbles of thunder are possible waking some of us up.
The girl's family asked for a sugary likeness of Frozen Princess Elsa - but instead received this.
Andy Murray has made it through to the Wimbledon quarter-finals after beating Ivo Karlovic 7-6 (9-7) 6-4 5-7 6-4.