PSA Tests for Prostate Cancer: What Your Results Mean

Photo Courtesy: SDI Productions/iStock

You may have heard the letters “PSA” mentioned by family, friends or your own doctor. PSA stands for prostate specific antigen, a substance made by the prostate. The prostate is a small organ in men, located beneath the bladder, that normally produces the fluid that sperm are released with. A PSA test can be performed to measure the levels of prostate specific antigen in your blood. High levels of PSA can be the first clue of prostate cancer.

There are many treatments available for prostate cancer. With early detection and treatment, patients with prostate cancer have excellent survival rates. In this article you can learn whether the PSA test is right for you and what your results mean.

Do I Need a PSA Test?

Experts recommend that men should get their PSA checked to screen for prostate cancer between the ages of 55 to 69. If you fall between this age range and you are concerned about the possibility of prostate cancer, the PSA test could be helpful. Younger individuals (40 to 54 years old) who are at a higher risk for prostate cancer may also benefit from PSA testing. You may have a higher risk for prostate cancer if you are African American, or have a family history of certain types of prostate cancer. If you think you have a high risk for prostate cancer, you should discuss the benefits and risks of PSA testing with your primary care doctor or a urologist (a doctor who specializes in treatment of prostate disorders).

If you are 70 years or older, or have a life expectancy determined to be less than 10-15 years by your physician, PSA testing is generally not recommended. This is because prostate cancer generally develops quite slowly, and the risks associated with PSA testing and prostate cancer treatments are not outweighed by the benefits at this age.

While testing your PSA levels is recommended for the groups above, there are risks and benefits. Deciding to get the test is a choice you should make after discussing these factors with your doctor.

How Is a PSA Test Done?

The PSA test is a blood test performed at a doctor’s office or lab. They will take a blood sample from your arm and analyze the amount of PSA in the sample. You can do this at the same time you are getting your blood drawn for your regular lab tests. After getting your blood drawn, the result will generally take one or two weeks to come back. Waiting for the results can be nerve-wracking, but try to stay busy to keep your mind off the results.

PSA Numbers and What They Mean

Your PSA is measured in nanograms per milliliter of blood (ng/mL). A normal PSA level for men can range depending on age. For men in their 50s or younger, a PSA of less than 2.5 ng/mL is considered normal. Since your PSA levels can rise normally with age, a PSA of less than 4.0 ng/mL is normal in those in their 60s or older. PSA levels that are higher than this or have risen dramatically from a previous PSA test may warrant further testing.

It is important to know that an abnormal PSA result does not always mean you have prostate cancer. If your PSA is between 4.0 and 10.0 ng/mL, there is a 1 in 4 chance that you have prostate cancer. If it is above 10.0 ng/mL, there is a 50% chance you have prostate cancer. Other than prostate cancer, several other conditions can cause elevated PSA levels:

  • Recent sexual activity
  • Normal aging
  • Non-cancerous growth of the prostate (also known as benign prostate hyperplasia)
  • Recent medical procedures near the prostate
  • Urinary tract infections
  • Infection of the prostate
  • Trauma to the groin

Your doctor will interpret your PSA results based on your age, medical history and symptoms to determine the next steps.

Next Steps After a PSA Test 

The next steps after a PSA test depend on many factors. If your PSA level was normal, your doctor will likely schedule another PSA test in two to four years if you are still within the age range to be tested.

An examination that your doctor may perform is a digital rectal exam to feel the prostate. During this examination your doctor will insert their finger into your rectum to feel whether your prostate has an abnormal shape, texture or size. While the digital rectal exam can be uncomfortable for some, it can help differentiate different causes of elevated PSA in some cases.

If your PSA was high, your doctor will take into consideration your age, medical history, lab results and examination to help determine whether you may need additional testing to determine the cause of elevated PSA. Additional testing may include repeating the PSA test after a few months to see how the level has changed.

If your doctor is concerned that you may have prostate cancer, they may recommend undergoing a prostate biopsy. During this procedure, a needle is placed into the prostate (while you are under anesthesia or numbed) to get samples. The samples are then visualized by a specialist under the microscope to determine whether or not you have prostate cancer. If you do have prostate cancer, you will most likely be referred to a doctor who specializes in the treatment of prostate cancer.

What Are the Risks and Benefits of a PSA Test?

While testing your PSA levels is recommended for the groups mentioned above, there are risks and benefits of getting the test. The PSA test is not a perfect test for detecting prostate cancer. As noted above, having a high PSA result does not always indicate prostate cancer. Deciding to get the test is a choice you should make with these risks and benefits in mind. 

The main benefit of getting a PSA test is that it is often the earliest detection of prostate cancer.

Since prostate cancer may not cause symptoms until it has become large or spread to other parts of your body, a high PSA can be the first clue to detecting prostate cancer early. When cancer is caught early and appropriate treatment is started, the life expectancy and survival rates are very high compared to other types of cancer. Treatment also greatly reduces the chance that prostate cancer spreads elsewhere in your body. The overwhelming majority of men diagnosed with prostate cancer that has not spread to other parts of the body live for more than 10 years after the diagnosis. However, without a PSA test prostate cancer could go undiagnosed until a later stage. 

The risks of PSA testing are false positive results, prostate biopsies and over-treatment of prostate cancer. A false positive means that your PSA level in the blood was abnormally elevated, but you do not actually have prostate cancer. PSA can be elevated due to the other conditions noted above, but a prostate biopsy is sometimes necessary to make sure there is no evidence of prostate cancer. The prostate biopsy procedure can result in pain, temporary blood in the semen, infection and, rarely, hospitalization. The prostate biopsy may also be indeterminate. 

In the case that the prostate biopsy shows that you have prostate cancer, treatment may be recommended. Treatment for prostate cancer can have unpleasant side effects. The side effects can include erectile dysfunction, difficulty controlling urination and stomach problems. Some individuals have less aggressive forms of prostate cancer that do not spread quickly. On the other hand, some prostate cancers may grow and spread quickly. A discussion with a specialist about this will help determine whether treatment is needed for prostate cancer, for how long, and how to best balance the side effects of medication with the beneficial effects of the cancer treatment.

Resource Links: