BIOMARKERS in seminal fluid have been found to be a more accurate indicator of prostate cancer than standard PSA testing, according to results from an Australian study.

Researchers from the Freemasons Foundation Centre for Men’s Health at the University of Adelaide tested semen samples from 60 men for a range of ribonucleic acid (RNA) molecules or microRNAs that are known to be increased in prostate tumours.

The men tested were already considered to be candidates for prostate cancer according to their prostate-specific-antigen (PSA) test results. Biopsy later confirmed that 32 of the men had cancer and 28 did not.

University of Adelaide research fellow and lead author of the study, Dr Luke Selth said that the results of the study indicated that, in the men tested, each of the micro-RNAs alone was a better predictor of a cancer diagnosis via biopsy than the PSA test. In addition, several of the micro-RNAs, when added to the PSA test results, were a better predictor of the presence of cancer than the PSA test alone.

Dr Selth said the results were promising both in terms of detecting the presence of cancer and identifying aggressive subtypes which could help to reduce both over-diagnosis and over-treatment of suspected prostate cancer.

“The presence of these microRNAs enabled us to more accurately discriminate between patients who had cancer and those who didn’t, compared with a standard PSA test,” Dr Selth said.

“We also found that the one specific microRNA, miR-200b, could distinguish between men with low grade and higher grade tumours. This is important because, as a potential prognostic tool, it will help to indicate the urgency and type of treatment required.”

The results add to previous research which indicated that microRNAs in blood can predict men who are likely to relapse after surgery for prostate cancer. The team have now applied for funding for a larger study into the role of microRNA biomarkers in predicting prostate cancer.

“We are not at the stage where we can say there is a new test for prostate cancer just around the corner,” Dr Selth said. “While these results are encouraging and exciting, we need to validate them in a much larger cohort.”

Endocr Relat Cancer 2014; online 23 May