The PSA Test
What is Prostate Specific Antigen (PSA)?
Prostate Specific Antigen (PSA) is a protein produced within the prostate gland and is secreted into seminal fluid.
There are two types of PSA:
Free PSA comes from benign prostatic hyperplasia (BPH), an enlargement of the prostate. The higher the amount of free PSA, the less likely prostate cancer will be found as prostate cancer cells produce more complex PSA.
- Free PSA: moves freely in the blood as it is unbound to other proteins
- Complex PSA: attached to other proteins as it moves around the blood
What is the PSA test?
The PSA test is a simple blood test, taken from the arm, which measures the amount of PSA protein in the blood. It is common for PSA to be found in the blood in very small concentrations. Higher levels of PSA may indicate the presence of cancer, but can also be an indicator of other prostate conditions.
Prostate Cancer Canada graciously acknowledges the Princess Margaret Cancer Centre for sharing this image with us.