Urologists test for the PCA3 prostate cancer gene by first completing a digital rectal exam and then analyzing a first-catch urine sample for the gene, according to Medical News Today. As of March 2015, the specific test used is the Progensa PCA3 assay.
The Progensa PCA3 assay requires a urologist to perform a digital rectal exam, which releases prostate cells into the urine, states the U.S. Food and Drug Administration. Test accuracy requires the immediate collection of a urine sample following the exam. The urologist processes the sample and sends it to a laboratory for the actual analysis. Laboratory technicians calculate the percentage of prostate cancer gene 3 RNA, which is produced by cancer cells, in comparison to the amount of prostate-specific antigen RNA, which is produced in equal amounts by cancer and normal prostate cells. A negative PCA3 score means that prostate cancer is unlikely.
Urologists use the PCA3 assay test on patients who have had negative prostate biopsies but still have symptoms that point to possible prostate cancer, maintains Mayo Clinic. The results are available in three to nine days. A negative PCA3 score means that a second biopsy is unnecessary. This prevents patient discomfort and complications from unnecessary medical procedures.