Causes of Elevated PSA Levels: It Does Not Always Indicate Cancer

Causes of Elevated PSA Levels: It Does Not Always Indicate Cancer
Page content

What is the Test For?

The PSA test – or prostate-specific antigen test – is a diagnostic test which can help diagnose prostate cancer. All men have low levels of PSA in their blood, but in most men with prostate cancer, the PSA level is elevated.

An elevated level of PSA in the blood is therefore one marker of prostate cancer, but it’s not the only one. In addition, there are non cancerous reasons for elevated PSA level, so if you test positive for elevated PSA, it does not automatically mean you have prostate cancer. In fact, according to the National Cancer Institute, only 35% of men who have a prostate biopsy following a positive PSA test actually have prostate cancer.

For a more in-depth explanation of the finer points of the PSA blood test, read Fasting PSA Blood Test and Prostate Cancer Screening.

Causes of Elevated PSA Test Results

A higher-than-normal level of PSA in the blood does not necessarily indicate prostate cancer, and there are several non cancerous reasons for elevated PSA level.

As men age, their prostates tend to become enlarged, even in the absence of any type of prostate-related disease or illness. Healthy prostates naturally produce small amounts of PSA, and as the prostate enlarges, it typically produces more PSA. Therefore, one of the possible causes for elevated PSA level is simply age-related prostate enlargement. In some cases, there may be no other factor causing the elevated PSA level, whether cancerous or not.

Because of this fact, age-based thresholds have been developed for PSA levels. This means that the normal baseline threshold for PSA level increases with age, to take account of the fact that normal PSA levels increase in older men.

As well as normal age-related causes of elevated PSA test results, there are some additional non cancerous reasons for elevated PSA level. An infection of the urinary tract (urethra or ureters) can cause an elevated PSA level, as can an inflammation of the prostate. Both of these conditions can cause significant increases in PSA levels. Smaller increases in PSA levels can be caused by ejaculation, and surprisingly, by bike riding.

Because there are many non cancerous reasons for elevated PSA level, this blood test is never used as the sole diagnostic criteria for prostate cancer. A rectal examination, for example, may be carried out to improve diagnostic accuracy. While only around one third of men with elevated PSA have prostate cancer, a man with an abnormal rectal exam and elevated PSA has around a 50% chance of a prostate cancer diagnosis.

References and Further Reading

Blood Testing and You: The PSA Blood Test

PSA Test Information at the National Cancer Institute

MedlinePlus: PSA Information

WebMD: Prostate-Specific Antigen (PSA) Blood Test