June 25, 2010
Dear Mayo Clinic:
I have had a PSA of 1.2 for many years. Now a year later my PSA is 2.1. Should I be concerned and check further? I am 67 years old.
Prostate-specific antigen (PSA) is a protein made by prostate tissue. Prostate cancer cells make excessive amounts of this protein, so an elevated or increasing PSA level is a possible sign of prostate cancer. That said, the answer to your question has many nuances.
A blood PSA level of 2.1 nanograms per milliliter (ng/mL) of blood is still in the normal range for a man your age. But the rapid increase in your PSA level is concerning and does merit some follow-up. A PSA increase of .75 or more in a year has been shown to be associated with prostate cancer. However, PSA readings similar to yours would rarely be associated with late-stage or symptomatic cancer. PSA readings are typically in the hundreds or thousands when patients first experience symptoms of prostate cancer.
Given your situation, a complete prostate exam is in order. In addition to taking a history, your doctor would conduct a digital rectal examination to check the prostate and look for signs of cancer or other causes of the increased PSA, such as inflammation or an enlarged prostate.
As men age, the prostate gland often enlarges, a condition called benign prostatic hyperplasia. It can cause urinary problems such as increased frequency of urination, the need to get up at night to urinate, decrease in the force of the urinary stream and an increase in PSA. Benign prostatic hyperplasia is not associated with cancer.
If there's no apparent reason for the increase in PSA, I'd suggest a recheck to see if the 2.1 reading was accurate. PSA levels vary somewhat day to day. If your PSA level is 2.1 or higher at the recheck, you and your physician should discuss further investigation.
If you are in generally good health and expect to live at least another 10 years, a biopsy to check for prostate cancer cells would be an option. In the past, biopsies were typically recommended when PSA readings were 4 or more. That guideline has been challenged in recent years, with some researchers recommending biopsies once PSA levels reach 2.6. In your case, it's the increase in PSA that might prompt a biopsy. Your overall health and expected life span are part of the discussion, too, because prostate cancer often grows very slowly and may not cause problematic symptoms for years.
If you undergo a biopsy and no cancer is found, you and your doctor would determine a follow-up schedule for PSA tests and prostate exams. The frequency of those rechecks would be based in part on your overall health, any family history of prostate cancer (if your father or brother has prostate cancer, your risk is increased), and your race (African American men have a greater risk of prostate cancer than do men of other races).
Another step to consider is taking medication to reduce the risk of prostate cancer. According to well-executed studies, men treated with 5-alpha-reductase inhibitors have a lower risk of being diagnosed with prostate cancer.
Finasteride (Propecia, Proscar) is one example of this type of medication. At lower doses, it's also used to restore hair loss. Though preliminary research is promising, finasteride has been shown to slightly raise the risk of developing higher grade prostate cancer. I offer finasteride to patients after discussing the risks and benefits. The medication is generally well tolerated. About 10 percent of men experience erectile dysfunction. This side effect disappears once the patient stops taking the medication.
PSA is not a perfect screening test for prostate cancer. It provides one clue in the process of detecting possible cancer. And the clue isn't always easy to interpret. You can also have prostate cancer without any change in the PSA level. The best advice is to learn all you can about your choices and work closely with your doctor to determine what's right for you.
—R. Houston Thompson, M.D., Urology, Mayo Clinic, Rochester, Minn.