Prostate Cancer - definitions

 There are a number of terms you will come across when reading about PSA tests. We will be adding definitions of the key terms that you will encounter.

We are starting with two of the more common terms: The Gleason Score and Free to Total 

What does the Gleason Score mean ?

 The higher the Gleason score, the more aggressive the cancer and the more likely it is to spread.

3+3 - All of the cancer cells found in the biopsy look likely to grow slowly.

3+4 - Most of the cancer cells found in the biopsy look likely to grow slowly. There were some cancer cells that look more likely to grow at a more moderate rate.

4+3 - Most of the cancer cells found in the biopsy look likely to grow at a moderate rate. There were some cancer cells that look likely to grow slowly.

4+4 - All of the cancer cells found in the biopsy look likely to grow at a moderately quick rate.

4+5 - Most of the cancer cells found in the biopsy look likely to grow at a moderately quick rate. There were some cancer cells that are likely to grow more quickly.

5+4 - Most of the cancer cells found in the biopsy look likely to grow quickly.

5+5 - All of the cancer cells found in the biopsy look likely to grow quickly.
Your doctor or nurse will talk you through what your results mean.

Source: Prostate Cancer UK 

Free to Total - Testing free and bound PSA

 

A standard PSA test measures the total PSA in the blood. But PSA has different forms. It can either be
Bound – attached to a protein in the blood
Free – not attached to a protein

We know from research that the proportions of free and bound PSA are different in men with prostate cancer, compared to men who have benign prostate disease. The general opinion is that a higher amount of free PSA in a test means a lower chance of cancer. Many doctors think that if more than a quarter (25%) of the total PSA is free, there is less chance of having prostate cancer. Put another way, men with prostate cancer are thought to have a lower proportion of free PSA.

So it is possible this test could help doctors find the cause of a raised PSA level. This might mean that some men with benign conditions avoid unnecessary biopsies. But methods of testing free and bound PSA in laboratories vary. And doctors are not agreed on the ratios of free to bound PSA that indicate cancer. So it is not used routinely in diagnosing prostate cancer. You are more likely to have it done if your standard PSA test result was borderline.