What Is Prostate-Specific Antigen?


What Is Prostate-Specific Antigen?

Prostate-Specific Antigen, or PSA, is a product of your prostate gland’s function. High PSA levels could be indicative of prostate cancer. Moreover, high levels could also indicate an enlarged prostate gland or prostatitis (infection of the prostate), which is a noncancerous condition. PSA is secreted by the prostate gland’s epithelial cells. Its purpose is to liquefy semen in the ejaculate to allow sperm to swim and reach their target. Even though it is intended to go into the semen, at times it can spill into the bloodstream. That is when a blood test is used to measure it.

psa levels

Factors That Affect the PSA Levels

Having a high PSA level could be due to several factors. Here are a few factors known to affect PSA levels:

1. Urinary Tract Infection or Irritation

If you have undergone any medical procedures involving the bladder or urethra, it may cause your prostate to produce more PSA. If this applies to you, it is important to give that area time to heal before going for a PSA test.

2. Age

Normal PSA levels tend to vary between people of different age groups. For example, older men’s regular PSA may be slightly higher than younger men’s.

3. Size of the Prostate

A healthy prostate produces lower levels of PSA. If a man has a larger prostate, they may have a higher level of PSA.

4. Medications

Some medications are known to reduce PSA levels, such as dutasteride, which is used as a medical treatment for benign prostate enlargement. It is highly recommended that you always let your physician know of all the medications you are currently taking.


Different Levels of PSA

Every individual can’t be assigned one level, because PSA levels vary among different age groups and ethnicities. In general, these numbers reflect known norms:

- If your PSA level is between 0 to 2.5 ng/mL, you have very little chance of having prostate cancer. That being said, some cancers may be present with a low level of PSA

- If your PSA level is between 2.6 to 4 ng/mL, you are still considered safe; but, it’s a good idea to speak to a professional about possible risk factors.

- If your levels are anywhere between 4 to 10 ng/mL, there is a possibility of prostate cancer.

- If the level is 10ng/mL or higher, this may be a sign of danger, so you should speak to a professional right away.

- If your annual PSA values show an incremental pattern, it is a concerning sign.

two ways

Free and Total PSA

There are two ways your PSA circulates through the body, either alone or bound to other proteins. The one that travels alone is called free PSA. As the name suggests, a free PSA test measures the free-floating PSA in the bloodstream whereas a total PSA test measures both free-floating and bound PSA. Both are meant to diagnose issues related to the prostate. However, if your free PSA percentage is low but the PSA level is high, your chances of having prostate cancer are high.

PSA Velocity

The change in PSA levels over time is called PSA velocity. If there is a rapid increase in PSA, it may be an indication of a serious form of cancer.

PSA Density

The PSA density is the serum PSA level divided by the prostate gland volume. It is usually performed at the time of diagnosis. To calculate PSA density, your MRI measurements of prostate volumes may be used. Prostate volume on the other hand is calculated using the transrectal ultrasound measurements.

Image: PSA levels can be useful to indicate if you have prostate cancer

Prostate Specific Membrane Antigen

PSMA or prostate-specific membrane antigen is a type of integral membrane protein that is connected in the prostate cancer epithelial cells. With PET or positron emission tomography imaging, PSMA is used as a phenotypic biomarker. It is present in around 80% of men who have prostate cancer.

psa screening

What Is Involved in a PSA Screening Test?

In a PSA screening test, blood is drawn from your arm and sent to a lab. Following that, you receive the results within a day or so.

PSA levels test

When Should I Get My PSA Levels Tested?

As per the American Cancer Society, you should ideally get tested between the ages of 40 to 45 if you are at high risk and the age of 50 if you are of average risk. Consult your physician about the pros and cons of prostate cancer screening, before deciding to get tested. Depending on your case, opinions may vary about when you should opt for it.

If there is a chance of you having prostate cancer, based on your rectal exam or PSA level, the next step is usually a biopsy. It is a test in which a small amount of prostate tissue from different sites is taken out from your prostate and sent to a lab for tests. This way, you can get treatment before the situation worsens.

Disclaimer: this blog post is provided for informational purposes and is not intended to replace the guidance of your personal physician. Please consult a medical professional if you have any concerns after reading this or other blog posts on this website.