One of the most challenging aspects of prostate cancer diagnosis is collecting urine samples from patients. In addition to being highly uncomfortable, post-digital rectal examination collection yields less than suboptimal samples. However, a new study suggests that the samples patients collect themselves at home may be at least equally reliable as current collection methods, not to mention a lot easier and more pleasant. The Diagnostic Challenge Measuring biomarkers contained in urine is the basis for diagnosing prostate cancer. Historically, a doctor collects a urine sample from the patient after performing a digital rectal examination of the prostate. The timing is important because the digital examination boosts the levels of prostatic secretion in the urine. However, research shows that the first urination of the day provides the highest and most consistent levels of biomarkers. The problem, of course, is that doctors rarely have access to that first-of-the-day urine. And home collection is unreliable and subject to sample spoilage and contamination. The New Test Researchers from the University of East Anglia (UAE) in the UK have pioneered a new test that enables detection of prostate cancer using urine samples that patients collect at home. The study, which was published in the published […]
One of the most challenging aspects of prostate cancer diagnosis is collecting urine samples from patients. In addition to being highly uncomfortable, post-digital rectal examination collection yields less than suboptimal samples. However, a new study suggests that the samples patients collect themselves at home may be at least equally reliable as current collection methods, not to mention a lot easier and more pleasant.
The Diagnostic Challenge
Measuring biomarkers contained in urine is the basis for diagnosing prostate cancer. Historically, a doctor collects a urine sample from the patient after performing a digital rectal examination of the prostate. The timing is important because the digital examination boosts the levels of prostatic secretion in the urine. However, research shows that the first urination of the day provides the highest and most consistent levels of biomarkers. The problem, of course, is that doctors rarely have access to that first-of-the-day urine. And home collection is unreliable and subject to sample spoilage and contamination.
The New Test
Researchers from the University of East Anglia (UAE) in the UK have pioneered a new test that enables detection of prostate cancer using urine samples that patients collect at home. The study, which was published in the published in the journal BioTechniques on November 29, 2019, demonstrates the effectiveness of a test called PUR (Prostate Urine Risk) in diagnosing aggressive prostate cancer and predicting whether patients will require treatment up to five years earlier than standard clinical methods.
But perhaps PUR’s greatest benefit is that it can be performed on urine samples collected at home. The PUR test uses a commercial preservative allowing samples to be maintained at room temperature without loss of RNA quality.
The Study
The research team provided 14 participants with an At Home Collection Kit, and instructions to collect urine samples after waking up in the morning. They then compared the results of their home urine samples with samples collected after a digital rectal examination.
Each sample was centrifuged at 2500 ×g for 5 minutes. Supernatant was filtered through a 0.8-mm filter, and the cell pellet was stored in 1 ml phosphate-buffered saline at -80°C. The researchers used the Qiagen RNeasy kit to extract RNA from the cell sediment. They then extracted cfRNA from urine supernatant via microfiltration (MicroF) or high-volume vacuum extraction (HiVE). They assessed RNA quantity using a Qubit 2.0 Fluorometer and Qubit RNA HS Assay. They then used a Bioanalyzer 2100 and the RNA 6000 Pico kit to assess RNA quality and an Agilent sRNA kit to measure sRNA yield.
Based on comparisons between digital rectal examination (DRE) and non-DRE urine RNA yields and RT-PCR expression levels, the researchers concluded that the collection of non-DRE urine by men at home was a viable and simple option. The research team found that the urine samples taken at home showed the biomarkers for prostate cancer much more clearly than after a rectal examination. And feedback from the participants showed that the at home test was preferable.
Takeaway: The researchers say they intend to use the PUR methodology and at-home collection protocol to develop a testing kit for aggressive prostate cancer within the next 10 years. “Being able to simply provide a urine sample at home and post a sample off for analysis could really revolutionize diagnosis,” notes lead researcher Dr. Jeremy Clark, from University of East Anglia’s Norwich Medical School. “It means that men would not have to undergo a digital rectal examination, so it would be much less stressful and should result in a lot more patients being tested.”
