Genetic Variations Key to Accurate PSA Testing

Queensland-led genetic analysis of 40,000 prostate cancer cases has made key findings that could improve the accuracy of the biomarker test for prostate cancer worldwide.

The QUT study, funded by Cancer Council Queensland, found that adjustments must be made for single genetic variations in the PSA gene when interpreting PSA test results for a prostate cancer diagnosis.

“The genetic variations we have found definitely affect the PSA levels and so if we want to develop a robust test that’s applicable to all ethnicities we need to identify the genetic variations with functional effect – it is time-consuming but we are making great progress,” said Dr Jyotsna Batra of the Australian Prostate Cancer Research Centre Queensland.

“Our ultimate goal is to use this information to improve PSA-based diagnostic tests which can reliably test men for prostate cancer and guide decisions about their treatment.”

Dr Batra and fellow researcher Professor Judith Clements of the Australian Prostate Cancer Research Centre Queensland analysed genetic data on 40,000 prostate cancer cases through the international Collaborative Oncological Gene-Environment Study (COGS).

“The most well-known and common diagnostic blood biomarker for prostate cancer is PSA (prostate specific antigen),” Dr Batra said.

“But the problem is that PSA picks up a lot of false positives for the fast-growing aggressive type of prostate cancer – between 15 per cent and up to 50 per cent can be wrongly identified as aggressive.

“Eighty-five per cent of prostate cancer tumours are benign and slow-growing.

“They grow over 10 to 15 years so these men and their doctors might prefer active surveillance because it is better to leave these tumours to preserve the person’s quality of life until it becomes necessary to actively treat them.

“But because the PSA biomarker cannot reliably tell us if a tumour needs treatment or not, the only way to confirm which type of tumour it is, is to do a biopsy which in itself can cause inflammation which has been associated with inducing cancer.

“We have recently identified a PSA functional genetic variation (known as a miRSNP) associated with prostate risk after analysing more than2000 miRSNPs throughout the genome (published in Cancer Discovery).

“Further analysis of more than 500 genetic variations within the PSA locus identified two additional prostate cancer associated SNPs, which can affect stability and activity of PSA as shown by preliminary data in our laboratory though a grant funded by Cancer Council Queensland.”

Cancer Council Queensland’s Professor Suzanne Chambers encouraged Queenslanders with any questions about prostate cancer to visit their GP, or call Cancer Council’s 13 11 20.

“Any questions about prostate cancer risks, diagnosis and treatment should be discussed with a GP or health professional on 13 11 20,” Prof Chambers said.

“We are proud to be funding this research at QUT, giving hope to Queenslanders who will be affected by prostate cancer in the future.

“We encourage those affected to talk to one of our qualified health professionals for information, support, advice, and emotional assistance.”

Prostate cancer is the most common cancer diagnosed in Queensland, accounting for nearly 1 in 3 of all male cancers and around 4000 new diagnoses each year.

Tragically, about 650 Queensland men die from the disease annually.

Call 13 11 20 or visit for more information.

For more information or interviews, please contact:

Katie Clift, Executive Manager, Media and Spokesperson, Cancer Council Queensland

Ph: (07) 3634 5372 or 0409 001 171