How to Interpret the Gleason Scale

If your PSA test results and/or DRE (digital rectal exam) comes up positive, the next course of action is usually a prostate biopsy (surgical removal of a small section of prostate cells).

The results of this test is referred to as your Gleason prostate score.

Your Gleason score for prostate cancer is a good indicator of your future response to treatment, your survival rate, and the best treatment for your prostate cancer.

How the Gleason Score is Calculated

The Gleason scale (1-5) is made up of a Gleason grade (1, 2, 3, 4, 5) from your prostate biopsy.

1 being the least aggressive and looking mostly like normal prostate cells, and 5 being the most aggressive and looking mostly like irregular prostate cancer cells.

Your Gleason score is based on combining the grades of two differant biopsy sections (primary and secondary).

- The primary section (at least 50% of biopsy).

Graded from 1 to 5.

- The secondary section (5% to 50% of biopsy).

Also graded from 1 to 5.

Therefore your Gleason score consists of 2 Gleason scale grades.

1 to 5 (primary) + 1 to 5 (secondary) = 2 to 10 (your Gleason score).

i.e. 4 + 3 = 7. A Gleason score of 7.

Gleason Score for Prostate Cancer Levels

- Low Grade (well differentiated): 4 or less.

- Intermediate Grade (moderately differentiated): 4 to 7.

- High Grade (poorly differentiated): 8 to 10.

Low Gleason Score: 4 or Less

Your biopsy test results indicate prostate cancer cells that still look like regular prostate cells and will tend to spread slowly.

Intermediate Gleason Score: 4 to 7

Your prostate cancer cells look somewhat like regular prostate cells but there are noticable differances, and may tend to spread at a faster rate.

High Gleason Score: 8 to 10

Your prostate cancer cells have clear indications of irregular shape and size, and may spread at a fast rate.

Prostate Cancer Treatments

Which treatment you and your doctor decide upon will depend on both your Gleason scores and stage of prostate cancer. The factors of whether the prostate cancer has spread outside your prostate gland and it's rate of growth, are the major determinants for the best treatment approach.