If you’re scheduled for a prostate biopsy, you will receive a Gleason score, which is a measure of how aggressively your cancer might behave. Pathologist Dr. Donald Gleason discovered this system in the 1960s. He founded the five different types of prostate cancer cells, ranging from least aggressive to most aggressive.
To begin, your doctor examines tissue samples from your prostate biopsy under a microscope. Your cancer tissue pattern will be compared with healthy tissue and assigned a grade on the Gleason scale of any number in the set 1 through 5.
- Grade 1 – The least aggressive type of cancer cell; it looks the most like normal tissue.
- Grade 2, 3, 4 – The most common tumor patterns on the scale; much like Grade 1, these tissues pose little danger of spreading quickly.
- Grade 5 – The most aggressive type of cancer cell and is recognized when the cancer tissues have spread through your prostate and differ widely from the features of healthy cells.
Many men have more than one prostate cancer cell type.
Every prostate cancer biopsy is assigned two numbers: the first is called the primary grade, it represents the most common type of cancer cell present. The second (or secondary grade) accounts for the second most common type of cancer cell present. The sum of these two numbers is your Gleason score, a number between 2 and 10. The best score you can get is two (1 + 1). The lower your Gleason score, the less dangerous your cancer and the most reasonable a conservative approach would be.
- Men with high Gleason scores (8 or greater) have a more dangerous and aggressive type of cancer. Their cancerous cells look very different from normal tissue, described as being “poorly differentiated.” This is still an early-stage prostate cancer since it has not spread, but if you are high-risk, it means your cancer is likely to grow or spread within a few years.
- A Gleason score of 6 or lower is considered low-risk. This means your prostate cancer is unlikely to grow or spread to other tissues and organs for some years. It is important that you know both of the numbers in your Gleason score. Discuss both your primary and secondary grade numbers with your doctor.
To help guide you to understanding your Gleason score and the significance of it and lead you to the best treatment for your condition, make sure you talk to your board-certified urologist about things other than your Gleason score.
- Gleason scores predict the rate your cancer will grow, not your prognosis.
- Make sure you also understand your cancer stage and your PSA level.
Understanding the whole picture is the key to zeroing in on the best treatment that suits your current condition.