At-Home Urine Collection as a Diagnostic Tool for Prostate Cancer
Posted: Friday, January 10, 2020
International research scientists have developed a new method to diagnose prostate cancer using at-home urine samples. The test reportedly predicts whether patients will require treatment up to 5 years earlier than standard clinical methods, according to Jeremy Clark, MD, of the University of East Anglia and the Norfolk and Norwich University Hospital, United Kingdom, and colleagues.
“Using our at-home test could in the future revolutionize how those on active surveillance are monitored for disease progression, with men only having to visit the clinic for a positive urine result,” stated Dr. Clark in an institutional press release. “This is in contrast with the current situation, where men are recalled to the clinic every 6 to 12 months for painful and expensive biopsies.”
The study, published in BioTechniques, used urine samples collected from men attending urology clinics at Norfolk and Norwich University Hospitals. All samples were collected with at-home kits before biopsy or 3 months after biopsy and prior to or after digital rectal examination. Upon receipt of the samples, RNA was extracted, amplified using reverse transcription polymerase chain reaction (PCR), then quantified by real-time PCR. The investigators showed that urine preservation is important by comparing RNA yields from preserved and nonpreserved samples, with up to 10% higher yields from preserved samples (P < .05).
The levels of known prostate cancer genes KLK2, PCA3, and TMPRSS2:ERG were compared between those collected from cells and those in cell-free vesicles, finding that levels of transcripts were higher in cell-free vesicles. According to the study authors, these transcripts originate in the cell-free fraction of urine, which may not require a digital rectal examination to extract.
The authors went on to compare urine samples between patients who had received the standard digital rectal examination prior to urine collection with those who had not received a digital rectal examination. The authors found the levels to be equivalent for KLK2 and PCA3; however, TMPRSS2:ERG was detectible more frequently in samples prior to digital rectal examination (P = .009).
Disclosure: The study authors reported no conflicts of interest.