Understanding Your Gleason Score
When you find out you have prostate cancer, your doctor may use some terms you’ve never heard before. One of these terms is Gleason score or Gleason grade. This is a helpful term to know because doctors use this score to understand and grade the level of your cancer.
Your Gleason score is based on results of your biopsy. During a biopsy, your doctor takes multiple samples of cells from both the suspected area of the cancer as well as uninvolved prostate to look at it more closely. Your doctor sends these specimens to a pathologist, a doctor who specializes in checking cells for signs of disease, including cancer. The Gleason score is named after the pathologist—Donald Gleason—who helped develop it in the 1960s.
Getting a Gleason Score
Many prostate cancers have areas with different grades. To get your Gleason score, the pathologist will look at the two largest areas of the cancer tissue and give a grade of 1 to 5 to each. These numbers rate how closely the cells look like normal prostate cells.
For example, if the cells look a lot like normal prostate cells, they get a grade of 1. Cells that look very abnormal get a 5. Those that fall in between get rated a 2, 3 or 4, depending on certain factors. The doctor adds these two numbers together to give your prostate cancer a Gleason score between 2 and 10. Most early-stage prostate cancers have a Gleason score of at least 6 or 7.
What the Numbers Mean
Once you have a Gleason score, your doctor uses that to predict how likely your cancer is to grow and spread. In general, the lower your score, the less likely your cancer will grow and spread.
- Gleason score between 2 and 6. These cancers are called low-grade, or well-differentiated. They often take many years to grow or spread.
- Gleason score of 7. These cancers are called intermediate-grade, or moderately differentiated. It often takes a few years for these cancers to grow or spread.
- Gleason score between 8 and 10. These cancers are called high-grade, or poorly differentiated. They are more likely to grow or spread in a few years.
Your Cancer’s Stage
Your doctor will use your Gleason score along with your prostate-specific antigen (PSA) level and the results of any other tests or exams you have had to determine the stage of your prostate cancer (an assessment of how far your tumor has spread). Doctors may order a CT, MRI, or other type of scan to further determine the stage. This is different from your Gleason score. Knowing your cancer’s stage helps you and your doctor choose which treatments are best for you.
Your Next Step
If you have any questions about your Gleason score or the stage of your cancer, make sure to ask your doctor. You may want to take notes, or to bring a friend or family member with you to your appointments to help you understand.