PSA testing: what’s normal?

PSA testing is often used to screen for prostate cancer. If your doctor has recommended that you have this screening, you may have questions about why you’re being screened, and what your results mean.

What is a PSA test?

A PSA test measures the level of prostate-specific antigen, or PSA, in a man’s blood. PSA is a protein that lives in the prostate gland. Some level of PSA exists in both healthy and malignant prostate cells, but the level is often elevated in men with prostate cancer.

The test is performed in the doctor’s office where a small blood sample will be taken. The sample will be sent to a laboratory for testing, and the results will be reported back to the doctor, who will share them with you.

Why and when is a PSA test recommended?

Doctors recommend PSA tests for a variety of reasons:

• To measure the progression of prostate cancer. Doctors often monitor PSA levels in patients who have had prostate cancer. Tracking PSA levels can help determine if the cancer has returned or continues to develop.
• As a follow-up test when patients have other prostate symptoms. Doctors may also recommend PSA testing to help identify prostate cancer in patients who have reported other prostate symptoms such as an enlarged prostate.
• To screen for prostate cancer. Today some doctors recommend PSA testing in otherwise healthy men over age 50 to test for early-stage prostate cancer. Some doctors and organizations, however, caution against this routine screening because it can identify the presence of small tumors that may never cause problems—and instead cause men to undergo treatment that can cause side effects such as impotence or incontinence. Medicare and many private insurers cover the cost of routine PSA screening.

What is a normal PSA level?

There is no specific normal level of PSA in the blood. In most men, PSA levels naturally vary over time. For several decades, most doctors considered PSA levels of 4.0 ng/mL and lower as normal. They would often recommend a prostate biopsy for men with a PSA level above 4.0 ng/mL. More recent studies have shown that some men with PSA levels below 4.0 ng/mL do have prostate cancer, and that many men with higher levels do not have prostate cancer.

As a general rule of thumb, the higher a man’s PSA level, the more likely it is that he has prostate cancer. And a continuous rise in PSA level over time may also be a sign of prostate cancer.

What does an elevated PSA level mean?

An elevated PSA level can indicate cancer, or—in patients who have already been treated for prostate cancer—it can indicate a return of cancer. However, several non-cancerous conditions can also cause a man’s PSA level to rise. These include prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (BPH, or enlargement of the prostate).

When a patient with no other symptoms of prostate cancer has an elevated PSA level, a doctor will most likely recommend further testing such as a digital rectal exam (DRE), as well as continued PSA screenings. If PSA levels continue to rise, or if a lump is found during DRE, a doctor may suspect prostate cancer and order a biopsy to test specific prostate cells for cancer. They may also test for other conditions such as urinary tract infection.

Sources:

Prostate-Specific Antigen (PSA) Test
The pros and cons of PSA screening