When it comes to screening for prostate cancer, the prostate-specific antigen (PSA) test has been the gold standard. But PSA testing is not perfect. It cannot distinguish prostate cancer from benign conditions that elevate PSA levels, for example.
In recent years, scientists have been trying to develop more accurate tests to supplement or replace PSA screening. One, which is still experimental, checks for the presence of PCA3, a molecule associated with prostate cancer, in urine. In February 2008, University of Michigan researchers reported developing another urine test that outperforms both PSA and PCA3 in distinguishing prostate cancer from benign conditions like prostatitis and prostate enlargement.
The Michigan team measured the expression of seven biomarkers associated with prostate cancer among 234 patients. By correlating the biopsy data with the urine test results, researchers found that four of the biomarkers were significant predictors of prostate cancer. In fact, the four together proved more accurate than either PSA or PCA3 alone, correctly identifying 80% of patients who were later found to have prostate cancer.
The next step: prove that these initial findings hold up in studies with more men at multiple institutions. Future efforts will also be directed at developing a urine test for biomarkers that might signal an aggressive form of prostate cancer.
SOURCE: Laxman B, Morris DS, Yu J, et al. A First-Generation Multiplex Biomarker Analysis of Urine for the Early Detection of Prostate Cancer. Cancer Research 2008;68:645–49. PMID: 18245462.
Originally published April 2009; last reviewed March 2, 2011.