Understanding Your Gleason Score and Your Grade of Prostate Cancer

Prostate cancer acts differently in each man. Grade is the word doctors use to describe how the cancer cells look under a microscope. The pathologist who looked at the cells obtained from your biopsy determines your cancer's grade. The most common system for grading prostate tumors is the Gleason scale.

What your Gleason score means

Doctors describe a prostate cancer's grade using the Gleason scale. This system uses numbers to tell the doctor how different the biopsy tissue looks from normal prostate tissue. The pathologist assigns a number from 1 to 5 to the two most common patterns of tumor cells from your biopsy. The two numbers are based on how the cancer cells look and how they're arranged. The two numbers are added together to form the Gleason score. This score helps your doctor figure out how aggressive the tumor may be. It doesn't show how far the cancer has already spread.

Gleason scores range between 2 and 10. Cancerous tissue that looks similar to the normal prostate is given a low grade. Very abnormal tissue is given a higher grade. Prostate cancers with low grades are less likely to spread to other organs than those with high grades. Cancers with a higher grade are considered more aggressive. Here's how the scores break down:

• Low-score cancers. Those with a Gleason score of 6 or less.

• Intermediate-score cancers. Those with a Gleason score of 7.

• High-score cancers. Those with a Gleason score of 8, 9, and 10. Cancers with a high score are aggressive tumors that are often difficult to cure.

Ask your doctor to explain the grade of your cancer because it will be important when you're deciding on treatment.