Due to these variables, the PSA is not considered to be a diagnostic tool or even an effective screening test when used alone. It is coupled with a digital rectal exam for prostate cancer screening, but ultimately, it is a prostate biopsy that either confirms or rules out cancer.
Other Than Cancer, What May Cause PSA Levels To Rise?Ejaculation -- While your doctor may not recommend avoiding ejaculation prior to having a PSA test, it can slightly elevate your levels. If your PSA level is high and you ejaculated within 48 hours of the test, your doctor may want to conduct a retest and ask that you abstain from sexual activity (or masturbation) before it.
Enlarged Prostate -- If you have benign prostatic hyperplasia (BPH), or an enlarged prostate, your PSA levels may be elevated. BPH is a common non-cancerous condition that occurs as men mature.
Prostatitis -- Another common culprit of high PSA levels, prostatitis is the inflammation or infection of the prostate. It can be caused by bacteria, but many times we don't know why some men develop prostatitis.
Age -- PSA levels can naturally increase as men grow older.
When Does a High PSA Warrant a Prostate Biopsy?In this excerpt, provided by UpToDate -- an electronic resource used by many patients and their doctors looking for in-depth medical information -- you can see how wary physicians may be to biopsy a prostate based on initial PSA test results:
"Men with abnormal PSA values can also be referred for biopsy, though some experts recommend first repeating the PSA several weeks later, particularly for borderline elevations below 7.0 ng/mL. PSA measurements have considerable short-term variability. A retrospective analysis of stored serum from 972 men found substantial year-to-year fluctuations with 44 percent of men with a PSA above 4.0 ng/mL having normal PSA findings at subsequent annual visits.
"In addition to biological variability, PSA may be transiently elevated due to ejaculation, perineal trauma, or prostatitis. Before repeating a borderline elevated PSA test, patients should be asked to refrain from sexual activity and bike riding for at least 48 hours and, if there is evidence of prostatitis, complete a course of antibiotics."
In most men, repeating a PSA test before undergoing biopsy is important, as many factors influence the level of PSA found in the blood. UpToDate references a study which found that many men who had elevated levels (above 4.0 ng/mL) had normal levels following the abnormal result. While having an elevated PSA result can be concerning, you should not panic. Want to learn more? See UpToDate's topic, "Prostate Cancer Screening," for additional in-depth medical information.
Hoffman, Richard M. "Prostate cancer screening." UpToDate. Accessed: October 2009.