PSA stands for Prostate Specific Antigen, a protein produced by the cells of the prostate gland. Its job is to help keep the semen liquid so the sperm can swim freely. PSA usually hangs around the prostate gland and semen, but small amounts can also move into the bloodstream and be measured by a blood test. You can have an elevated PSA if your prostate becomes inflamed for any reason as a result of infection or BPH.
The PSA test is also one of the methods used to detect prostate cancer as elevated levels of PSA are present in the blood of men who have the disease (although there are other reasons for an elevated PSA unrelated to cancer). Note there may be no symptoms of prostate cancer but still have an elevated PSA.
The PSA test can also be used to help to determine if a particular prostate therapy has been effective by monitoring the amount and change in PSA levels after treatment for cancer, including surgery, radiation, chemotherapy, or hormone therapy.
The PSA test is undertaken via a simple blood test as part of a prostate screening decision made between you and Dr. Alarcon. Until recently, a PSA level less than 4.0 ng/ml (nanograms per milliliter) was considered normal and safe. Today the safe limit is thought to be lower than that, but no one is quite sure what that level should be.
Because of these arbitrary guidelines, many men with PSA levels slightly greater than 4.0 used to undergo prostate biopsies and other advanced diagnostic tests designed to detect prostate cancer. However, studies revealed that 65 to 75 percent of men who had elevated PSAs who underwent prostate biopsies did not have prostate cancer, while some men who had so-called “safe” PSA levels did have cancer. At this time, the medical community still has not reached a consensus on which PSA levels are “safe,” “suspicious,” and “dangerous”.
Doctor Alarcon agrees however that the risk of finding prostate cancer rises as the PSA levels goes up. According to the American Cancer Society, a PSA level between 4.0 and 10.0 ng/ml means a man has about a 25 percent chance of having prostate cancer, while a PSA greater than 10.0 ng/ml indicates about a 50 percent risk. Remember, however, that these numbers reflect risk only: many men who have elevated PSA levels do not have prostate cancer.
PSA Velocity and Density – A Relatively New Concept
In the past, physicians relied heavily on the absolute PSA level (or one single number) to decide whether prostate cancer had been eliminated, whether it had returned after treatment, and how extensive the disease was among other things. However, it became apparent that relaying just upon the absolute PSA level fails in some important ways. That is why some doctors (including Dr. Alarcon) may also use other PSA values – such as PSA velocity and PSA density – to get a more accurate idea of what was happening with the prostate
PSA Velocity
PSA velocity is a measurement that considers annual changes in PSA values. Such changes tend to rise more rapidly in men who have prostate cancer than in those who do not. Measuring a man’s PSA velocity can be useful in detecting prostate cancer in its early stages. It can also help to keep better track of men who have mildly elevated PSA levels and a normal digital rectal exam. Finally, PSA velocity can also help in predicting a return of prostate cancer when PSA changes are followed over multiple years.
PSA Density
PSA is produced by prostate cells – whether they are normal or cancerous. Men who have larger prostates, logically, have more prostate cells and, in general, produce more PSA. To correct for this, the PSA level is then divided by the size of the prostate to calculate the PSA density. A low PSA density means that a large volume of prostate tissue is making relatively little PSA. A high PSA density means that a relatively small volume of prostate tissue is making a lot of PSA. Overall, men found to have a high PSA density likely should be more vigilantly monitored for prostate cancer, and Dr. Alarcon would retain a higher level of suspicion about abnormalities found on the digital rectal exam and about an increase in PSA.
Is a Low PSA Good?
Generally speaking, a low PSA is a good result. However, if your PSA level is “artificially” pushed down, it could hide a rising PSA level that otherwise would be noticed and investigated. If you take a statin drug to lower your cholesterol or you regularly use a nonsteroidal anti-inflammatory drug, such as ibuprofen or aspirin for headache or muscle aches, for example, these drugs can result in a “pushed down” PSA level. The same effect can occur if you are obese, which may be the result of body fat decreasing the amount of PSA that is in circulation in the bloodstream. Therefore if you fit into either of these categories, your PSA test results may not be as reliable a reflection of your prostate’s health as it could be. Thus it is important to tell Dr. Alarcon if you are taking any of these medications.
What Causes a High PSA?
Some factors that can cause an elevated PSA have nothing to do with an unhealthy prostate. The PSA test is also not always 100 percent precise, and test results may vary from lab to lab. In addition, if your prostate gland naturally happens to be very large or very small, your “normal” PSA level may be a bit higher or lower than the accepted average. So what’s normal for you may not be normal for the average man.
Many factors can cause a rise in a PSA level, such as:
- Advancing age
- Prostate biopsy or surgery
- Catheterization (have been recently catherized)
- Urinary tract infection
- Urinary tract surgery
- Use of certain chemotherapy drugs
- Recent ejaculation and having too much sex
- Sports supplements taken by athletes (especially body builders)
- Riding a bicycle
- Sports injuries
- Pelvic injury or trauma to the prostate
- Prostatitis (and the symptoms associated with it)
- An enlarged, noncancerous prostate gland (BPH)
- Prostate cancer (and the symptoms associated with it)
What if my PSA is High?
For men with a “high” PSA Dr. Alarcon will typically choose to do additional tests that may initially include:
- Digital Rectal Examination (DRE)
- Transrectal Ultrasound
- MRI Scan
- Prostate Biopsy
If no disease is found after any additional tests Dr. Alarcon may recommend ways to lower your PSA as part of a general approach to a healthy lifestyle.