New prostate cancer test cuts need for biopsy

New blood test helps assess cancer risk more accurately, and can tell if cancer is aggressive

For half the men who show up for prostate cancer screening at Tan Tock Seng Hospital (TTSH), the results are inconclusive and a biopsy is recommended.

But it is costly to take these tissue samples and, in some instances, the procedure can result in problems such as incontinence or erectile dysfunction.

To solve this problem, the hospital has started carrying out another test for those whose screening results fall within a certain range.

It is estimated that this will save a third of patients the trouble of undergoing a biopsy.

"Biopsies are uncomfortable, and they can cause bleeding or severe infections," said Dr Tan Yung Khan, who is a consultant at the hospital's urology department.

"If we can avoid doing biopsies, that's a good thing."

Prostate cancer is the third-most common cancer among men in Singapore, with 3,694 new cases diagnosed between 2010 and last year.

Under the basic screening test, which measures the level of a certain chemical in the blood, those who score in a certain range have a 25 per cent chance of having prostate cancer.

However, this test is "not very specific", said Dr Tan. A higher score could mean cancer, but it could also mean the man has an enlarged prostate or a prostate infection.

The new blood test, which is being used as a secondary screening measure, combines the results of three different tests for a more accurate assessment of the patient's cancer risk. It can also tell doctors whether the cancer is slow-moving or aggressive.

The new test is not used as a primary screening measure because of the cost - the first test costs around $30, while the new one will cost around $100.

But Dr Tan said he estimates that its greater accuracy could reduce the number of biopsies, which cost $500, by a third.

The hospital carries out 700 biopsies for prostate cancer a year.

"If we can reduce the number of biopsies by a third, that's a huge burden lifted," Dr Tan said.

A version of this article appeared in the print edition of The Straits Times on November 13, 2015, with the headline 'New prostate cancer test cuts need for biopsy'. Print Edition | Subscribe