Published in Nature Communications, a new study led by the University of Minnesota Medical School and Duke University found that a DNA sequencing test for advanced prostate cancer patients can distinguish between patients with poor and favourable prognoses.

The new blood-based test—called AR-ctDETECT—is designed to detect and analyse small fragments of tumour-derived DNA in the blood of certain patients with advanced, metastatic prostate cancer.

In this new study, the AR-ctDETECT test was used to analyse DNA from more than 770 blood samples from a phase 3 clinical trial of advanced prostate cancer patients. The test identified circulating tumour DNA (ctDNA) in 59% of patients with metastatic prostate cancer. Patients with detectable circulating tumour DNA had significantly worse overall survival compared to those without. These results demonstrate the potential of the AR-ctDETECT test to provide key genetic information to tailor treatments based on similar characteristics among patients.

"Our AR-ctDETECT test, designed for prostate cancer, shows how valuable these blood tests could be in helping doctors better understand a patient's cancer and predict how the disease will progress, leading to more personalised treatment plans," said Scott Dehm, PhD, a professor at the U of M Medical School and member of the Masonic Cancer Center.

The study concluded that detecting ctDNA using AR-ctDETECT provides critical prognostic insights for patients with metastatic prostate cancer.

"The AR-ctDETECT assay is a comprehensive panel focused on genes relevant to prostate cancer and hormone resistance, particularly the androgen receptor and critical structural alterations not currently detected by other commercial tests," said Andrew Armstrong, MD, a professor at Duke University School of Medicine, an oncologist with Duke Cancer Institute and co-senior author on the study.

"Incorporating genomic profiling into clinical decision-making may enhance personalised treatment strategies and inform the design of future clinical trials."

"Our team demonstrated the ability of AR-ctDETECT to effectively identify distinct groups of patients based on their genomic profiles," said Susan Halabi, Ph.D., a James B. Duke Distinguished Professor of Biostatistics at Duke University School of Medicine.

"Notably, our study is the first to demonstrate, within a phase 3 cohort, that metastatic prostate cancer patients with positive ctDNA treated with standard therapies had worse overall survival compared to ctDNA-negative patients."

Further research will focus on integrating genetic data from the AR-ctDETECT test with patient clinical data to improve patient prognostication. The research team also plans to evaluate whether the AR-ctDETECT test could be used to predict patient outcomes in the context of specific treatments, which could be used in the future to guide optimal therapy.