The PSA (prostate specific antigen) blood test is used to look for prostate problems. Only the prostate makes this chemical in any quantity and some of it can be detected in the blood. An elevated level suggests that there may be a prostate problem. This problem may be an enlarged prostate, an inflamed or infected prostate or prostate cancer. The higher the level of the blood test, the more likely that cancer will be diagnosed.
Because the PSA test can be raised in a number of different prostate conditions, it is useful, but can be difficult to interpret, and may lead to a number of other tests designed to prove or exclude the presence of cancer. Ideally only men that would benefit from being treated for prostate cancer should have a PSA test and this should be discussed with a Doctor before a test.
The PSA blood test is traditionally a test that takes several days for the laboratory to process before that result is available, however there is also a rapid test available that uses a pinprick blood sample. Both these tests have been used by the Staffordshire Urology Clinic, but we usually use the laboratory test as it is more accurate.
A raised PSA blood test may need further tests to prove or exclude the presence of prostate cancer. A urine sample may be requested to exclude infection and a repeat PSA test is often requested to ensure that the first was a true reading. If the PSA is raised without an obvious source of infection or inflammation an MRI of the prostate is usually suggested. This test is designed to measure the size and detect cancer of the prostate. The MRI is not totally accurate and a biopsy of the prostate is usually the next step. Again a negative set of biopsies does not completely exclude prostate cancer. Prostate biopsy can be performed through the back passage (transrectal) or through the perineum skin (transperineal).