The PSA blood test is often the first step in screening for prostate cancer. It is included in a two-part screening process that also includes the digital rectal exam (DRE). Since the PSA is not prostate-cancer specific, abnormal results are further, or an elevated PSA is not a diagnosis for cancer. Things like evaluating a patient, knowing their medical and family history, following a PSA trend, as well as the velocity at which PSA changes can help a physician make an informed decision about what an elevated PSA might mean. Because PSA tests are not necessarily straightforward, simple or easy diagnostic tools, knowing the risk factors and tracking the changes in PSA can help you and your physician interpret a PSA properly.
So why doesn’t a PSA blood test mean cancer, if that is how we screen for prostate cancer? The truth is, that a PSA alone is not an informative enough diagnostic tool to distinguish between prostate cancer and other benign prostate conditions. An elevated PSA can be the result of benign conditions such as prostatitis or an enlarged prostate. Other factors that affect the interpretation of a “high” PSA are things like age, ethnicity, and family history of prostate cancer. The only way to diagnose prostate cancer is with a prostate biopsy.
So besides prostate cancer, what else can cause a PSA to rise, fluctuate or become elevated?
- Age: PSA levels can increase gradually as you age
- Prostatitis: Inflammation of the prostate gland, due to infection or some unknown cause
- Benign prostatic hyperplasia (BPH): This condition refers to an enlarged prostate. More prostate means more cells making prostate specific antigen, increasing the potential for an elevated PSA.
- Urinary tract infection: can irritate and inflame prostate cells and cause PSA to go up
- Medications: Some medications like Proscar, Avodart, or Propecia can falsely lower your PSA. This too is important to remember. If you are on any of these medications, talk to your doctor. The general rule of thumb is to double your PSA for an accurate score.
- Sex/ejaculation: This can cause a mild elevation in the PSA, but should return to normal after a few days.
- Prostate trauma: Anything that causes direct trauma to the prostate such as riding a bike, having a catheter in, a prostate biopsy, or a bladder exam can significantly increase the PSA temporarily.
Seeing as there are many different things that can cause an elevated PSA aside from prostate cancer, it is important to evaluate each patient individually and thoroughly. The next step after an elevated PSA is not necessarily a biopsy, as the PSA is NOT diagnostic of cancer. Rather, it is a “red flag” to bring attention to a potential issue. Further treatment, as in a biopsy, depends on how high the PSA is and how much it’s changed from previous readings. Coupled with a detailed history and physical, a urologist may be able to identify the cause of the elevated PSA. After evaluating the overall clinical picture, a physician can recommend a biopsy to rule out cancer, antibiotics to treat an infection, or a scope procedure to evaluate the size of the prostate.