Most of my male patients undergo routine, annual PSA (prostate specific antigen) testing. 9 times out of 10, the result comes back within range of normal, or negative as does their physical exam. At other times, a PSA test may come back as elevated, outside of the normal range, and then I have the unpleasant task of calling these patients and giving them potentially very scary news.
PSA testing is one of the best medical screening tools available to detect cancer of the prostate, but there is a two-sided debate about its true value. With current PSA testing, we have to deal with results that could be false negatives versus false positives. That is, your PSA testing that comes back from the lab as “abnormal”, or out of normal range, but may not be anything for you to be concerned about. On the other hand, you may have “normal” lab results and have symptoms or physical findings that warrant further testing.
First, for those of you who have yet to have a PSA test done, let’s talk about what PSA testing is and how it can benefit a man.
What Is Prostate Specific Antigen (PSA) Testing?
Prostate Specific Antigen (PSA) testing is a blood test that measures PSA, a substance made by the prostate gland. PSA testing is done by a simple blood test performed in your doctor’s office. The normal range falls between 1-4 nanograms of antigen per milliliter of blood. This is where the debate stems from as a “normal” blood result does not always assure you are cancer free.
In a recent study, 15.2% of men with lower than 4 PSA results were diagnosed with a high grade cancer. Symptoms, and/or lump on physical exam alone, can prompt a closer look with additional testing, such as ultrasound, cystoscopy, or surgical biopsy, even with normal ranges. Generally, however, the 1-4 scoring system is usually accurate for a disease-free prostate. Now, let’s talk about the other side of the coin, an elevated PSA.
Does An Elevated PSA Level Always Mean Cancer?
When I see a higher than normal range PSA level result, there are other factors that also need to be considered like:
Age: The older a man is, the more at risk he is for prostate cancer which may raise a red flag but doesn’t necessarily mean his high PSA level will show cancer. In a younger man, elevated PSA levels may be more a result of other factors that can drive up PSA numbers like those listed below.
Race: Hispanic males are at greatest risk for prostate cancer, though the reason for this is not clear. African-American males are second-highest at risk, white males next, with Asian/Pacific Islander, Native Americans at less risk.
Infection: A urinary tract infection, or infection in another part of the body, can throw off PSA testing, causing it to be high even though there may be no evidence of cancer.
Inflammation: Inflammation of the prostate or the surrounding area can also falsely elevate a PSA test.
Enlarged prostate (benign, or noncancerous): A condition called benign prostatic hypertrophy can also cause a false elevation of the PSA test.
Symptoms: As mentioned above, symptoms alone can prompt further testing in a normal PSA result. In contrast, a man may have a high PSA level and have no symptoms at all!
Digital rectal exam: If a lump or other abnormality is felt in the prostate gland during a rectal exam, with a normal PSA level, this will prompt further testing.
New Technologies and Recommendations
Even though current PSA testing is not a perfect science, and its results can be skewed by many factors, it is still one of the best screening tools we have for detecting early prostate cancers.
New technologies are being developed to address the current inadequacies of regular blood PSA testing. These include PSA velocity which measures rises in PSA over time; PSA density which compares the level of PSA with the size of the prostate; free PSA versus attached PSA which can more clearly show a benign prostate enlargement rather than possible cancer; lowering the PSA “normal” cut off to 2.5 instead of 4 in the hopes of finding prostate cancers that are overlooked.
Whichever modality is used, I recommend that, starting at age 40, men get an annual prostate screening exam, which consists of both a PSA test, and a digital rectal exam. Or, even if you are younger, if you have any of the following symptoms, please see your doctor to be screened:
- Difficult urination – starting, stopping flow; weak stream
- Frequent urination – especially having to get up a few times a night
- Blood present in the urine or semen
- Pain upon ejaculation
- Constant pain in the lower back, hips, pelvis
Some wonder what is the value of a PSA test in the first place if it can register false readings and cause even more anxiety in patients and/or put them through further testing that may not be necessary. I feel the answer lies in using the PSA as only one tool in addition to good detective work on the part of your doctor to determine false negatives or positives.
Take heart in the fact, though, that most men with elevated PSA results read false positive and do not have cancer. Only about 25-30% of all men who have further testing, like ultrasound and biopsy, actually turn out to have cancer. Further, over 1.8 million men are survivors of prostate cancer as the result of early screening! And that’s a real positive that you can trust.
Mark Rosenberg, M.D.