Scientists in the U.K. say they have developed the first reliable test for diagnosing early prostate cancer.
The urine test is so accurate that it could be used to screen all older men for the disease.
Scientists at the University of Surrey identified a protein called EN-2, which is only produced by prostate cancer cells.
Studies show a test for the protein detects 60 to 70 percent of cancers.
But the false positive rate – men who are wrongly diagnosed with cancer – is just 4 percent.
On both counts, the new test is vastly superior to the existing PSA blood test, which detects fewer than 40 percent of cancers and has a false positive rate of over 50 percent.
"I think the lack of false positives is clearly very, very encouraging,” Professor Hardev Pandha, who led the research, told Sky News. "The technology that underlies the test is so simple that actually having a desktop apparatus in a GP's surgery would be very, very straightforward. It's very exciting."
Early indications also suggest high levels of EN-2 in the urine indicate aggressive tumors that need immediate surgery.
Men with lower levels could be monitored, avoiding the need for an operation, which can cause impotence and incontinence.
Dr. Richard Morgan, who also developed the test, said it was a significant step forward in the fight against prostate cancer.
"In conjunction with other tests and clinical signs of cancer, I think it will have a very important part to play in diagnosis and in monitoring the disease," he said.
The scientists hope to have the EN-2 test is in widespread use in the next 12 to 18 months.
In the United States, prostate cancer is one of the most common types of cancer in men.
According to the National Cancer Institute, there were 217,000 new cases of prostate cancer in the U.S. in 2010, and more than 32,000 deaths.
Scientists describe their findings in the journal Clinical Cancer Research.