The prostate cancer antigen 3 gene (PCA3) test is used to help determine your risk of prostate cancer. It is not used to diagnose prostate cancer.
It’s mainly used to determine if your elevated prostate-specific antigen (PSA) levels are likely caused by prostate cancer. PSA is a protein produced by cells in your prostate. Elevated levels of this protein could indicate a harmless problem with your prostate, such as an enlarged prostate. But elevated PSA levels can also indicate prostate cancer.
The PCA3 test can help identify a genetic marker in your urine. If you have the genetic marker and elevated PSA levels, the elevated levels are more likely to be caused by prostate cancer than by another condition.
Results from a PCA3 test can help you and your doctor decide if they should take a biopsy of cells in your prostate gland. A biopsy is a tissue sample used to confirm a diagnosis. The test is especially useful in men who have had previous negative prostate biopsy. It can help determine if further biopsies are necessary.
Keep reading to learn more about this test and what to expect.
What’s the difference between the PCA3 test and the PSA test?
The PCA3 test measures the levels of prostate cancer gene 3. This gene is found in high levels in prostate cancer cells. The test isn’t affected by an enlarged prostate, prostatitis, or other conditions of the prostate gland.
PSA tests measure the levels of prostate-specific antigen in your blood. If your levels are high, or if they rise rapidly, you may have prostate cancer. But elevated PSA levels can be caused by many things besides prostate cancer, including:
- benign prostatic hyperplasia (BPH), often referred to as an enlarged prostate, which is a common, noncancerous condition
- prostatitis, or inflammation or infection of the prostate
- urinary tract infections
- pressure on the prostate from a digital rectal exam or catheter
PSA tests used to be given annually to men older than 50 years, but they’re no longer recommended as a primary screening method by most medical experts. There are several reasons for this:
- There are a high number of false positives with PSA tests.
- Some men have prostate cancer even when their PSA levels are low, so the test may give false negatives.
- In many men, prostate cancer grows so slowly that watchful waiting is advised rather than treatment.
- Because the diagnosis of cancer can be alarming, some men have unnecessary biopsies or surgery.
- Incontinence and sexual problems can be common side effects of prostate cancer treatment.
The PCA3 test is not a substitute for PSA testing, however. PCA3 testing is used along with PSA tests and others. It’s not currently being used for prostate cancer surveillance among the general population. Currently, PSA remains the preferred test for monitoring prostate cancer.
The PCA3 test’s primary use is to provide more information than PSA testing and a digital rectal exam can provide. This will help you and your doctor make better-informed treatment decisions. It may also help you avoid unnecessary biopsies.
PCA3 vs. PSA
- PSA tests can detect both benign and cancerous conditions of the prostate.
- The PCA3 test detects prostate cancer cells better than PSA tests because it is more specific for prostate cancer.
- PSA tests remain an important marker in the management of prostate cancer.
Who should have the test?
Having a PCA3 test done in addition to a PSA test and digital rectal exam can more accurately assess your need for a biopsy of your prostate gland. The decision to have the PCA3 test is up to you and your doctor.
Generally, the test is given if you have elevated PSA levels but a biopsy found no cancer. It’s also given if you and your doctor have decided that watchful waiting is the best strategy, but you want another method of monitoring your status.
What happens during the test?
Your doctor will start by giving you a digital rectal exam (DRE). They will insert a lubricated, gloved finger in your rectum and gently push on your prostate gland. This helps move the PCA3 into your urethra so it can be expelled in your urine. Following the DRE, you’ll be asked to provide a urine sample. The urine sample will be sent to a lab for testing and the results will then be sent to your doctor when they are available.
The PCA3 test results are more accurate when preceded by a DRE.
The PCA3 test costs, roughly, between $200 and $450. Prices vary depending on the manufacturer of the test and your location. You’ll probably have a fee for at least one office visit or consultation, as well.
Check with your insurance company before having this test. Medicare and many insurance companies do not pay for PCA3 testing.
How to understand your results
Your results will include a PCA3 score. The higher your score, the greater your probability of having prostate cancer. That means that a higher score will likely mean your doctor will recommend a biopsy to confirm a cancer diagnosis.
|PCA3 score||Risk of prostate cancer|
|Less than 35||The risk is low risk. Your doctor is unlikely to recommend biopsy.|
|35 or higher||You have increased risk of prostate cancer. Your doctor will likely recommend a biopsy.|
In addition to your PCA3 score, your doctor will look at your overall risk factors when determining your need for a biopsy, including your:
- race and ethnicity
- PSA levels
- digital rectal exam findings
- biopsy history
- family history
What happens after the test?
After you have a PCA3 test, your doctor will discuss the results with you and suggest next steps. If the test results show a high score, it’s likely the doctor will recommend that you have a biopsy.
If you’re diagnosed with prostate cancer, especially if it’s discovered in an early stage, your long-term outlook is very good. After discussing with their doctors, many men choose not to have treatment for their prostate cancer. Instead they adopt watchful waiting, in which their prostate tests are monitored closely for signs that the cancer may be progressing.