A prostate cancer urine test can identify men at intermediate risk who can safely avoid immediate treatment, a study has suggested. Scientists say these men could instead benefit from active surveillance.

A pilot study by researchers at the University of East Anglia (UEA) revealed how urine biomarkers could show the amount of significant cancer in a prostate, highlighting with more certainty which men need treatment.

Previously, the team's prostate urine risk (PUR) test could identify men with high and low risk cancers, but it can now help men with intermediate-risk disease – for whom treatment options had been less clear.

Prostate cancer is the most common cancer in men and usually develops slowly, with the majority of cancers not requiring treatment in a man’s lifetime.

However, it is difficult for doctors to predict which tumours will progress to a more aggressive form, making it hard to decide on treatment for many men, experts suggest.

Lead researcher Dr Jeremy Clark, from UEA’s Norwich Medical School, said: "Previously we have shown that PUR can identify men with high-risk cancer which requires immediate treatment and also low-risk cancer that has a very low rate of progression and does not generally need treatment.

"But there is a third category of men with 'intermediate-risk’, which falls in between these extremes.

"Around half of men diagnosed with prostate cancer fall into this group and the treatment pathways for them have been less clear, until now."

He added: "PUR will also be useful for monitoring disease in men that do not currently require treatment and flag up the emergence and expansion of aggressive disease."