Screening hundreds of proteins in prostatic secretions from prostate cancer patients allowed researchers to identify protein signatures capable of detecting prostate cancer and distinguish aggressive from benign forms, paving the wave for a urine sample test to diagnose the disease.
The study, “Targeted proteomics identifies liquid-biopsy signatures for extracapsular prostate cancer,” published in the journal Nature Communications, is a significant step toward a future where prostate cancer can be diagnosed without the need for invasive biopsies — a necessary evil of today’s diagnostic processes.
In an earlier study comparing two different prostate cancer groups, the research team had identified no fewer than 624 proteins in prostatic secretions. Such secretions can be obtained through a urine sample collected after a digital rectal examination.
Building on this work, a new joint effort between researchers from the Ontario Institute for Cancer Research (OICR) and University Health Network (UHN) in Toronto, Canada, and Eastern Virginia Medical School allowed the team to narrow down the large number of proteins to 133.
Testing the validity of the proteins in a group of 74 individuals, divided into two types of prostate cancer patients, healthy controls, and men with prostate enlargement enabled further selection. The research team then tested a group of 34 proteins in a new group of patients and controls, for a total of 207 individuals.
Thorough tests and validation experiments led researchers to conclude two signatures — one indicating the presence of prostate cancer, and the other to assess the aggressiveness of the cancer.
“The amazing thing about these signatures is that their rate of accuracy is as good or better than the invasive tests that are used today, with far fewer drawbacks,” said study co-author Dr. Paul Boutros, a principal investigator at OICR, adding the test would present an economical option to frequently monitor patients with benign cancers, doing away with risky biopsies and unnecessary surgeries.
Reza Moridi, Ontario’s minister of research, innovation and science, also expressed his appreciation for the research and congratulated the scientists on the work they did.
“Your collaboration demonstrates the kind of world-class research taking place in Ontario that will soon pave the way for future advancements in the fight against prostate cancer,” he said.
The method is now undergoing further validation studies before entering clinical trials.