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
The NHS is at "breaking point" with declining numbers of beds compounding the situation, according to the British Medical Association.
Donald Trump's ambiguous phrase "what's happening in Sweden" during a rally on Saturday was a reference to a Fox News story, he has claimed.
Donald Trump's revised immigration ban targets the same seven Muslim majority countries listed in his original executive order, sources say.