Prostate Cancer PSA Info

Prostate Cancer PSA

Prostate-Specific Antigen (PSA) Test

What is the prostate-specific antigen (PSA) test?

Prostate-specific antigen (PSA) is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in the blood. It is normal for men to have a low level of PSA in their blood; however, prostate cancer or benign (not cancerous) conditions can increase a man’s PSA level. As men age, both benign prostate conditions and prostate cancer become more common. A man’s PSA level alone does not give doctors enough information to distinguish between benign prostate conditions and cancer. Why is the PSA test performed?

Doctors often use the PSA test and DRE as prostate cancer screening tests; together, these tests can help doctors detect prostate cancer in men who have no symptoms of the disease.

A man who has been treated for prostate cancer should discuss an elevated PSA level with his doctor. For whom might a PSA screening test be recommended?

Several risk factors increase a man’s chances of developing prostate cancer. How are PSA test results reported?

PSA test results show the level of PSA detected in the blood. In one large study, however, prostate cancer was diagnosed in 15.2 percent of men with a PSA level at or below 4.0 ng/mL (2). What if the screening test results show an elevated PSA level?

A man should discuss an elevated PSA test result with his doctor. There can be different reasons for an elevated PSA level, including prostate cancer, benign prostate enlargement, inflammation, infection, age, and race.

What if the test results show a rising PSA level after treatment for prostate cancer?

A man should discuss rising PSA test results with his doctor. Most men with an elevated PSA test result turn out not to have cancer; only 25 to 35 percent of men who have a biopsy due to an elevated PSA level actually have prostate cancer (3).

Why is the PSA test controversial in screening?

The benefits of screening for prostate cancer are still being studied. PSA velocity: PSA velocity is the change in PSA level over time. More studies are needed to determine if a high PSA velocity more accurately detects prostate cancer early.

PSA density: PSA density considers the relationship between the level of PSA and the size of the prostate. The use of PSA density to interpret PSA results is controversial because cancer might be overlooked in a man with an enlarged prostate.

The free PSA test is more often used for men who have higher PSA values. Free PSA may help tell what kind of prostate problem a man has. If a man’s attached PSA level is high but his free PSA level is not, the presence of cancer is more likely. What other methods are being studied to detect prostate cancer?

Some research also suggests that the microRNA patterns in early-stage prostate cancer and late-stage prostate cancer may be different.