What is the Gleason Scale?

The Gleason scale enables the likely aggressiveness of prostate cancer to be measured. A sample of prostate cells that have been gathered from a prostate biopsy are looked at histologically using a microscope. The cells are then given a Gleason score based upon how similar they look to a normal prostate cell, with a Gleason grade of 1 given to cancer cells that look like normal prostate cells and a grade of 5 given to the most abnormal and undifferentiated cancerous cells.

A look at Gleason Grades

Gleason grade 1 is often called well-differentiated, in this case the cells look very similar to healthy cells. These types of cancer cells are likely to be of a less aggressive nature as they are slow growing.

Gleason grade 3 – moderately differentiated cells; at this grade cancerous cells may have invaded surrounded prostate tissue. This is the most common grade of prostate cancer.

Gleason grade 5 – undifferentiated cells, at this stage cancer cells bear no resemblance to normal cells. These cancer cells are likely to be fast growing and likely to spread quickly.

Gleason grades 2 and 4 are intermediate grades

The Gleason Score

When looking at the prostate cells through the microscope the technician will give a grade to the two areas most affected by cancer; these two grades can then be added together to produce a Gleason score. As the Gleason scale runs from 1 to 5 it follows that Gleason score results are on the scale of 2 to 10. By looking at two different areas it is possible to establish the likelihood of prostate cancer spreading and the likely growth rate.

Gleason scores are typically given in the form of Gleason 3 + 3 = 6 or Gleason Grade 3 4 Gleason score 7.

When looking at your Gleason scoring it is important to realise that the first number represents the largest area of cancerous cells seen. For example a Gleason score 6 given as 4 + 2, would be considered more aggressive than one of 2 + 4 as a larger area of cells have aggressive undifferentiated cells in the first case.

It is hoped that the information given on the prostate Gleason scale will hope you to better understand the results from a prostate biopsy. If there is any thing that you are unsure of then do not be afraid to talk this through with your doctor.


© Prostate Cancer Guide inc. 2006 - 2014