In a promising breakthrough, a team of scientists at Johns Hopkins University has developed a noninvasive urine test that can detect prostate cancer with outstanding accuracy. This new “liquid biopsy” offers hope for replacing or augmenting the traditional PSA blood test, which can lead to many false alarms and unnecessary invasive procedures.
For years, the PSA (Prostate-Specific Antigen) blood test has served as the first line of screening for prostate cancer, but it is far from perfect. High PSA levels can result not only from cancer, but also from benign conditions such as prostate enlargement or inflammation, leading to false positives and anxiety for many men.
The new approach works differently. Instead of measuring a protein in the blood, the researchers looked for tiny pieces of genetic material, RNA, that cancer cells shed into urine. After detailed genetic analysis, they discovered many RNA signals that differ between men with cancer and those without.
From an initial pool of hundreds of RNA signals, the team narrowed the list down to three key RNA markers: TTC3, H4C5, and EPCAM. These three markers, when combined, form a “signature” that can distinguish cancerous from non-cancerous cases.
They tested this signature in two groups. In the first, smaller group of 243 men, the test achieved a sensitivity of about 94 % and specificity of 86 %, with an “area under the curve” (AUC) of 0.96. In the larger validation group of 646 men, the sensitivity was about 91 % and the specificity about 84 %, with an AUC of 0.92.
These results suggest the urine test is both good at catching true cancer cases and good at ruling out men without cancer. Importantly, the test also distinguished cancer from benign prostate conditions better than PSA tests, which could reduce the number of unnecessary biopsies.
While the findings are encouraging, more work remains. The researchers point out that larger, prospective clinical trials are needed before the test can become a standard tool in hospitals. Still, the simple urine test represents a major advance in prostate cancer detection. If widely adopted, it could ease patient anxiety, cut down on invasive procedures, and help doctors detect serious cancers earlier and more reliably.
