New biomarker for prostate cancer could help guide treatment pathways

Scientists believe they may have unearthed a potential new way of testing how advanced a patient’s prostate cancer is and whether it is responding to treatment.

QIMR Berghofer Medical Research Institute senior research officer Dr Carolina Soekmadji said the presence of certain molecules in patients with advanced prostate cancer could provide a more accurate picture of their prognosis than the current test.

Dr Soekmadji said testing for those molecules could provide an individualised map of prostate cancer progression that was more precise than the current, widely-used prostate-specific antigen (PSA) serum test.

She said the molecules, known as extracellular vesicles (EVs), were potential biomarkers that provided information on the lipid, protein and nucleic acid content within a patient’s cells.

“The development of new biomarkers that can give doctors an accurate and up-to-date picture of treatment response for advanced prostate cancer is vital,” Dr Soekmadji said.

“This is particularly so because one of the commonly used treatment regimes, Androgen Deprivation Therapy (ADT), has so many unpleasant side-effects.

“By looking at these molecular biomarkers within the body, doctors could potentially gauge what level of treatment a patient needs.

“We also hope that clinicians may one day be able to use this information to tailor therapies to suit the biological background and make-up of each individual patient.”

Dr Soekmadji said the presence of EVs provided a source of accurate genetic and environmental information on the progression of advanced prostate cancer.

She said the secretion of a particular type of EV molecule was found to be higher in patients with prostate cancer than it was for men who had an enlarged but benign prostate.

She said the same molecules were found in higher numbers in patients with advanced prostate cancer, alongside circulating tumour cells (CTCs).

Dr Soekmadji said a high CTC count indicated a poorer prognosis for prostate cancer that had already spread around the body.

“While further investigation is needed, this tells us that the presence of EV molecules could be important not only as a prostate cancer biomarker for diagnosis and prognosis but in order to make a more informed prediction of treatment response,” Dr Soekmadji said.

“It is still early days and more work needs to take place, but our indicative findings are very promising.”

She said the newly-identified biomarkers for prostate cancer could theoretically be measured via a simple blood test.

Dr Soekmadji said the identification of new biomarkers that could give a more complete picture of prostate cancer progression, was an exciting prospect.

She said ADT, a common hormonal treatment for advanced prostate cancer, often caused multiple side-effects including hot flushes, decreased libido, erectile dysfunction, the development of breast tissue, abdominal obesity and osteoporosis.

“Many patients with advanced prostate cancer do not respond well to Androgen Deprivation Therapy, while others do experience treatment benefits,” she said.

“If we can identify who is more likely to respond well, and who is likely to respond poorly, we can recommend a particular treatment regime that is ultimately better for the patient.

“Our next step is to measure EV levels and identify molecular trends in a larger group of patients with advanced prostate cancer.”

Dr Soekmadji said she was already working with researchers in Melbourne to identify additional biomarkers in a larger pool of men with advanced prostate cancer.

The QIMR Berghofer research, published in the journal The Prostate, was conducted with the University of Melbourne, Princess Alexandra Hospital, Queensland University of Technology, the Translational Research Institute, the Australian Prostate Cancer Collaboration Bioresource and Erasmus Medical Centre in The Netherlands.

Dr Soekmadji was supported by a Movember Foundation grant and by the United States Department of Defence Congressionally Directed Medical Research Program.