Urine test improves prostate cancer screening

Testing for the prostate cancer gene 3 (PCA3) in urine improves screening for prostate cancer. Screening of prostate cancer usually involves measuring a protein in the blood called prostate specific antigen (PSA). High PSA levels suggest that cancer may be present and a biopsy is then performed to confirm the diagnosis. Unfortunately, in some men with a high PSA, the biopsy comes back negative, confusing doctors whether the patient does not have cancer or whether the cancer was missed in the biopsy. Men with elevated PSA levels, but negative prostate biopsy results, form a diagnostic dilemma. Unlike PSA, which can be elevated with benign as well as malignant prostate disease, PCA3 appears to be specific for prostate cancer. In a recently study, researchers from the University of California in Los Angeles assessed the ability of urine PCA3 testing to detect prostate cancer in 233 men with elevated PSA levels and at least one prior negative prostate biopsy. A PCA3 score was determined for each subject using a highly sensitive quantitative test. This score was then compared with PSA testing in predicting the outcome of the repeat prostate biopsy. Overall, 226 of the men had adequate amounts of genetic material in their urine to facilitate PCA3 analysis. Sixty of the men had prostate cancer on repeat biopsy. The researchers found that the PCA3 score was more accurate than the PSA test at predicting whether the repeat biopsy would show cancer. In men with elevated PSA levels and previous negative prostate biopsy findings, the determination of the urinary PCA3 levels appears to have value in detecting prostate cancer.