Blood Testing for Prostate Cancer

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A prostate-specific antigen (PSA) test is a blood test that measures a protein released in the blood by prostate cells. Both normal and cancerous prostate cells release the protein. Most of the time, high PSA levels are due to conditions other than cancer. Examples include an enlarged prostate (benign prostatic hyperplasia) or inflamed prostate (prostatitis). But a high PSA level can be a sign of prostate cancer.

How a PSA Test Can Screen for Prostate Cancer 

A PSA test is the most common prostate cancer screening test. Screenings are done to check for a condition in people with no symptoms and are often incorporated into a wellness visit or annual checkup for men over 45. The higher your total PSA level, the more likely you are to have prostate cancer. Keep in mind, though, that some men who have prostate cancer do not have a high PSA. Along with screening for prostate cancer, physicians may use PSA tests to:

  • Help find the reason for prostate symptoms
  • Check if prostate cancer has come back or is getting worse in men already known to have it

Fred Hutch’s prostate cancer specialists recommend the following screening schedule:

  • Men under 40: Digital rectal exam (DRE) and PSA screenings are not recommended for men at average risk.
  • Men 40 to 54: DRE and PSA screenings are not recommended for men at average risk.
  • Men 55 to 69: DRE, PSA or both screenings may be right for you. Talk with your physician about the risks and benefits.
  • Men 70 or older: DRE and PSA screenings are generally not recommended. But men who are in excellent health may benefit from screening.

If you are higher risk than average, talk with your physician to find out if you should be screened and at what age.

PSA Tests and Overdiagnosis

Among health care providers, there has been concern that PSA screening can lead to overdiagnosis of prostate cancer and potential overtreatment. Overdiagnosis is the diagnosis of cancer by screening that would not have been diagnosed without screening in the patient’s remaining lifetime. Overtreatment is the treatment of cancer that may not impact overall health or lifespan. Increasingly, active surveillance is a viable option for many men with low-risk prostate cancer.

At Fred Hutch Cancer Center, we believe there are several good reasons to do PSA screening.

  • It helps detect early-stage disease. Thanks to PSA screening, more men begin care when their prostate cancer is in the early stages and it may be curable.
  • Prostate cancer deaths have decreased. Deaths from prostate cancer have gone down by about 40% since the start of PSA screening, as shown in a National Cancer Institute investigation.
  • Testing can be done selectively. Together, men and their physicians can decide when to do PSA tests — and what to do about the results. It’s true that PSA screening uncovers many cases of prostate cancer that may not need to be treated, like low-risk cancers in older men. Younger men who appear healthy are most likely to benefit from screening. Getting a diagnosis doesn’t mean they’ll be overtreated. Many people should opt for active surveillance or watchful waiting.

Why Choose Fred Hutch and UW Medicine for PSA Tests

Your Fred Hutch provider may perform a PSA test as part of your diagnosis or assessment. PSA tests are typically performed by a primary care provider or specialist. Our care partner, UW Medicine, offers a range of options, including appointments with leading urologists. 

Explore UW Medicine Primary Care Options
Fred Hutch Sloan Clinic
Fred Hutch Sloan Clinic

Prostate Cancer Blood Testing FAQ

The test itself isn’t risky, but there may be some risks to getting the results. For example, the test might detect prostate cancer that would never have caused you any symptoms or threatened your life. If you get treatment for cancer in this situation, you may have procedures that don’t really benefit you but could cause side effects or complications.

With any test, there’s also a chance of a false positive — in this case, finding a high PSA level when there’s no actual cancer. This could worry you and lead you to get other care you don’t really need, like a prostate biopsy. Or you could get a false negative — meaning, your results seem normal even though cancer is present.

The main benefit of a PSA screening test is to find cancer at an early stage. Early-stage cancers have not spread yet and may be easier to treat or monitor for changes.

A PSA test is a simple blood test, so the experience is like getting blood drawn from a vein in your arm for other lab tests.

The timing for the results of a PSA varies based on where the results are analyzed. It can be as short as the same day or up to more than a week. Fred Hutch usually returns results within 1-3 days.

There are PSA test kits that you can use at home. You collect your own blood sample. Then you send it to a lab, which gives you the results. But this doesn’t give you a chance to talk with your physician about whether screening makes sense for you or what the results mean. There’s no PSA level that clearly means you have prostate cancer (or another condition). If you opt to test at home, discuss your results with your physician. Ask if you should have further testing or take any other steps.

Most urologists consider the following PSA levels to be normal.

  • Men younger than 60 : Total PSA of 2.5 ng/mL or lower
  • Men 60 or older : Total PSA of 4.0 ng/mL or lower 

Talk with your physician to decide the best next step in your situation. Common options include:

  • Repeating the test in one to two months to see if the level is still high. If it is, your physician might suggest doing repeat PSA tests and DREs to see if anything changes.
  • Having other blood tests, urine tests or imaging tests.
  • Having a prostate biopsy to check for cancer cells.

If your total PSA is high or abnormal, your physician might use one of these tests to decide if you need a biopsy:

  • Free PSA level: A free PSA test checks for PSA in your blood that is not bound to other proteins. This is a subset of your total PSA. Your free PSA level is divided by your total PSA to get the percentage of free PSA. A result of less than 10% means you have a higher risk for prostate cancer. The lower the percentage, the higher the risk.
  • Prostate health index (PHI): A PHI is a blood test to detect and predict how likely you are to have prostate cancer. It uses two of your PSA subset values to create a cancer risk ratio. Studies of the accuracy of this test are ongoing. 
  • Urinary PCA3 test: This is a urine test for proteins specific to prostate cancer. Unlike PSA, PCA3 is made only by prostate cancer cells (not in healthy prostate cells). The level is not affected by your prostate size. This test can be used along with total and free PSA tests. Physicians use it more often in men whose biopsy did not show cancer to decide if they should have another biopsy. 
  • Multiparametric MRI: This is a specialized magnetic resonance imaging (MRI) scan of your prostate. It’s done to find areas that look suspicious so your physician can target these areas during your biopsy (a method called MRI-fusion biopsy). Physicians use this test most often in men whose earlier biopsy did not show cancer but whose PSA level is rising or causing ongoing concern. It’s possible to have a normal MRI but still have prostate cancer. So, physicians often do biopsies even when MRI results appear normal.