PSA stands for Prostate-Specific Antigen, a protein produced almost exclusively by cells in the prostate gland in men. PSA is normally secreted into the seminal fluid to help liquefy semen; however, a small amount also enters the bloodstream, where it can be measured with a blood test.

PSA levels in the blood can rise due to a variety of prostate-related conditions, including prostate cancer, benign prostatic hyperplasia (BPH) and prostatitis (inflammation or infection of the prostate). Additionally, several lifestyle factors, such as recent ejaculation, vigorous exercise, or certain medications, may also elevate a PSA test.

Elevated PSA is not specific to cancer, but it can be a valuable early warning signal that something in the prostate needs closer evaluation.

Why Does PSA Rise in Cancer?

In prostate cancer, the normal architecture of the prostate tissue is disrupted. This disruption allows more PSA to leak into the bloodstream, not necessarily because the cancer cells produce more PSA, but because the natural barriers that normally contain PSA within the prostate are broken. As a result, a higher level of PSA may be detected in the blood, which can prompt further testing.

However, it’s important to remember:

A high PSA does not always mean cancer, and a low PSA does not always rule it out. PSA is one part of the overall picture, and your doctor will consider your age, risk factors, PSA trends, and other findings to decide if additional tests are needed.