A saliva test may help "turn the tide" on prostate cancer, UK scientists claim.
It analyses men's DNA to work out who was born with the greatest risk of developing the disease.
Targeting them for prostate biopsies and MRI scans discovered some aggressive cancers that would otherwise have gone unnoticed.
However, the test has not yet been proven to save lives and experts say it will be "years" before such tests could be used routinely.
Around 12,000 men in the UK die from prostate cancer every year.
Calls for the routine testing of healthy men – known as screening – have grown louder since Olympic cyclist Sir Chris Hoy announced he had terminal prostate cancer.
Screening has been rejected in the past because using the current test – which looks for levels of prostate specific antigen (PSA) in the blood – risks causing more harm than good.
