A newly published article in BJU International has described a way to test post-DRE urine samples for the presence of specific types of ribonucleic acid (RNA) and use these data to detect and classify risk levels for more and less aggressive forms of prostate cancer.
The full text of this new article by Connell et al. is available on line, and is also discussed in a whole series of media articles (see here and here for examples).
It should be noted that the only other test that has ever been based on post-DRE urine samples (the so-called PCA3 test) never really met the promise that it seemed (at first) to hold. One question obviously relates to the “vigorousness” with which a DRE has to be carried out prior to collection of the urine sample. However, …
The new test described by Connell et al. does seem to hold out cconsiderable promise if the data can be validated in prospective trials moving forward.
What we know at the present time is basically the following:
- The research team set out to develop prostate urine risk (PUR) signatures for four subsets of men:
- Men with normal prostate tissue, and no evident risk for prostate cancer (PUR-1)
- Men with D’Amico low-risk prostate cancer (PUR-2)
- Men with D’Amico intermediate-risk prostate cancer (PUR-3)
- Men with D’Amico high-risk prostate cancer (PUR-4)
- Urine samples from 535 men collected at multiple centers were used to create the PUR signatures.
- The signatures were based on analysis of post-DRE urine samples for levels of urine‐derived extracellular vesicle RNA (EV-RNA).
- This model was then applied to a test cohort of men (n = 177) for diagnostic evaluation, and to an active surveillance (AS) sub‐cohort of men (n = 87) for prognostic evaluation.
The researchers report the following core results:
- Each PUR signature was significantly associated with its corresponding clinical category (P < 0.001).
- PUR‐4 status predicted the presence of clinically significant intermediate‐ or high‐risk disease.
- Application of PUR provided a net benefit over current clinical practice.
- In the AS sub‐cohort (n = 87), groups defined by PUR status and proportion of PUR‐4 had a significant association with time to progression.
- When used continuously over time, PUR‐4 status was able to differentiate between patient groups with progression rates of 10 percent and 60 percent at 5 years after urine collection (hazard ratio [HR] = 8.23; P < 0.001).
The authors conclude that:
Urine‐derived EV‐RNA can provide diagnostic information on aggressive prostate cancer prior to biopsy, and prognostic information for men on AS. PUR represents a new and versatile biomarker that could result in substantial alterations to current treatment of patients with prostate cancer.
Clearly more information will be needed before such a test might be available in routine clinical practice. It might also be more helpful if PUR status could be more closely correlated to the current six NCCN risk categories as opposed to just the original three D’Amico risk categories. This might take some time to accomplish. However, the ability to use urine samples with accuracy as a way to assess risk for prostate cancer (as opposed to biopsy samples requiring genomic testing) would me a major step forward.
Filed under: Diagnosis, Management, Risk | Tagged: Diagnosis, prognosis, PUR, risk. classification, test, urine |
THE "NEW" PROSTATE CANCER INFOLINK 
Hope they can develop this test. I’m not a fan of the PCA3 test. After my first negative biopsy in 2001, had two PCA3 tests because of slightly rising PSA. Both showed no indication of prostate cancer. A biopsy in 2012 was positive (6 out of 12 cores, Gleason 4 + 3 = 7). Surgery in 2012; radiation in 2013. Knock on wood: no need for hormones yet.
Dear Paul:
Other than the test’s commercial providers, I am no longer aware of anyone who is a “fan” of the PCA3 test. It is relatively rare for me to hear of any patient who has been given this test in the past 3 years.
I am a very active, 150 lb, vegetarian, white, male, aged 78.
My father died of prostate cancer at age 79. My PSA has gone from 4 to 9.7 in the last 10 years. My percent free PSA is holding steady at 10. My Prostate Health Index or phi score in last 2 years went from 60 to 100. My symptoms are slow drainage and average nocturia of ~1.2. My DRE indicated a nodule.
I have heard that PCA3 requires a vigorous DRE to stir up PSA. I have heard that the rectum wall is extremely delicate. I refused the vigorous DRE and I did not do the PCA3. My 3T-MRI showed two areas of PI-RADS 4. My 4KScore is 83.
Is PUR better?
Dear Jerry:
There is no way to answer that question at the present time. However, …
Because your father died of prostate cancer, because you have a PI-RADs score of 4, and because you are otherwise healthy and active with a likely life expectancy of another 10+ years, many specialists would probably tell you that it would be sensible of you to talk to your doctors about getting a biopsy done under MRI/TRUS fusion guidance. You have several signals of potential risk for clinically significant prostate cancer. Data from the PUR test (even if it was available, which it isn’t outside of clinical trials at this time) is highly unlikely to change that fact.