Urine Test Identifies Tumor Grade Prostate Cancer
Despite its common use, the PSA blood test cannot distinguish between low-grade cancer and high-grade cancer. Low-grade cancer can be monitored and does not need active treatment whereas high-grade cancer requires surgery and radiation therapy.
A new urine test that can detect genetic changes correlated with prostate cancer correctly identified cancer grade in 92% of men with elevated prostate-specific antigen (PSA) levels had high-grade cancers.
A new study, published in JAMA Oncology compared a urine-based gene expression assay with biopsy results from 499 patients.
The study noted that in 66% of men with low-grade cancer, the new test incorrectly predicted high-grade cancer. In a clinical practice, the use of this test would have saved 27% of men from undergoing unnecessary prostate biopsies.
Given the pain and risks associated with performing a prostate biopsy, that is not a trivial thing. This is the only urine-based experiment that does not need a rectal digital examination before collection. The new test could reduce hundreds of thousands of invasive biopsies each year and it is easy to integrate into the clinical setting.
“The test has the potential to be a significant improvement over PSA alone in distinguishing between low- and high-grade prostate cancer, especially in the PSA gray-zone patient,” said James McKiernan, MD, the John K. Lattimer Professor and chair of urology at Columbia University Medical Center and urologist-in-chief at New York-Presbyterian/Columbia, New York City, and first author of the study.