If you find out that you have prostate cancer you may wonder how likely it is that the cancer could spread. To help answer this question, your healthcare team uses the Gleason score and grade group from your biopsy report.
The Gleason score and grade group are numbers that tell your healthcare team whether your prostate cancer is growing slowly or quickly. The numbers also help your healthcare team choose your treatment options.
Here's some information to help explain where these numbers come from and what they might mean for your prognosis and your treatment options.
What is the Gleason score?
The Gleason score is a number that tells the healthcare team whether prostate cancer cells are likely to grow slowly or quickly. It's only used for adenocarcinoma, which is the most common type of prostate cancer. Other types of prostate cancer don't get a Gleason score.
Where does the Gleason score come from?
A cancer's grade is a number that tells the healthcare team how different the cancer cells look from healthy cells. For prostate cancer, the care team uses the grade to figure out the Gleason score and grade group.
To get the cancer's grade, doctors in the lab, known as pathologists, look at the prostate tissue samples taken from your biopsy under a microscope. They check how your cells look compared with healthy prostate cells. Cancer cells have different sizes and shapes, which also are called patterns. The pathologists find the two most common patterns of cancer cells in the sample and assign grades to them.
If the cancer cells look similar to healthy cells, then the cancer cells are low grade. Low-grade cancer grows slowly. If the cancer cells look very different from healthy cells, then the cancer cells are high grade. High-grade cancer grows quickly.
What are the grades of prostate cancer?
Prostate cancer grades range from 3 to 5. The range starts at 3 because grades 1 and 2 are no longer used.
Cells of Gleason grades 3, 4 or 5 are cancer. The medical term for this is malignant. Grade 3 is the lowest grade of prostate cancer. Grade 5 is the highest grade of prostate cancer.
- Grade 3. This cancer grade is the least serious. The cells are a mix of sizes and shapes. Some cells are evenly spaced and some cells are fused together in large, oddly shaped clumps. These cancer cells are the least aggressive. This means that the cancer cells typically grow slowly. The cancer cells are not likely to spread.
- Grade 4. Many cancer cells are fused into clumps. The cells also can form large, round clusters with holes in the middle. Grade 4 tumors are more aggressive than grade 3 tumors. The cells can spread to nearby tissue.
- Grade 5. This cancer grade is the most serious. Most of the cancer cells have gathered into large masses and have no definition. These cancer cells are the most aggressive. This means that the cells typically grow quickly. They are at a high risk of spread or have already spread to nearby tissues or distant parts of the body.
How is the Gleason score calculated?
To calculate the Gleason score of a prostate biopsy, pathologists add the most common grade from the samples with the highest grade from the samples. To get the Gleason score from prostate tissue removed during surgery, pathologists add the most common grade and the second most common grade.
A Gleason score looks like a math equation such as 3 + 4 = 7. In this example, the first number is the most common cancer grade in the tissue sample. The second number is the next most common cancer grade. The third number is the Gleason score.
Gleason scores range from 6 to 10. A score of 6 means that the cancer is growing slowly and has a low chance of spreading. A score of 10 means that the cancer is growing quickly and has a high chance of spreading.
What are the grade groups?
The grade group also is a number that tells the healthcare team how fast the cancer cells are likely to grow. The grade group is based on the Gleason score and it gives the same information, but it might be easier to understand.
What does each grade group mean?
The grade groups range from 1 to 5 and are based on the Gleason score. Your healthcare team uses the grade group to help plan your treatment.
- Grade group 1. The Gleason score is 6 or less. This is the least serious and lowest grade group of cancer. The cancer cells grow slowly. They are the least aggressive. This means that the cancer cells aren't likely to spread. The pattern is 3 + 3.
- Grade group 2. The Gleason score is 7. The cancer cells are mostly slow growing, but there's a small portion of cells that are aggressive. The cells have a low chance of spreading. The pattern is 3 + 4.
- Grade group 3. The Gleason score is 7. More grade 4 cancer cells are present. The cancer is more aggressive and more likely to spread. The cancer also is more likely to come back after treatment. The pattern is 4 + 3.
- Grade group 4. The Gleason score is 8. Cancer cells are aggressive. They have a high chance of spreading if they aren't treated. The cancer also is more likely to come back after treatment. The patterns are 4 + 4, 3 + 5 and 5 + 3.
- Grade group 5. The Gleason scores are 9 and 10. This is the most serious and highest grade group of cancer. The cancer cells grow quickly. They are the most aggressive. The cancer cells are likely to spread and come back after treatment. The patterns are 4 + 5, 5 + 4 and 5 + 5.
Why do two grade groups have the same Gleason score?
Gleason scores in grade groups 2 and 3 each equal 7. But their differences are important. What matters most is how many grade 4 cancer cells are present and what they look like.
Grade group 3 has more grade 4 cancer cells than does grade group 2. The cancer cells are typically more aggressive and more likely to spread. The cancer also is more likely to come back after treatment.
The higher the Gleason score and grade group, the higher the risk of aggressive cancer:
Risk level | Gleason score | Gleason grade group |
Low risk | 6 | 1 |
Intermediate risk | 3 + 4 = 7 | 2 |
Intermediate risk | 4 + 3 = 7 | 3 |
High risk | 8 | 4 |
High risk | 9 and 10 | 5 |
Based on Clinically localized prostate cancer: AUA/ASTRO guideline (2022). American Urological Association. https://www.auanet.org/guidelines-and-quality/guidelines/clinically-localized-prostate-cancer-aua/astro-guideline-2022. Accessed Dec. 18, 2025; Dmochowski RR, et al., eds. Campbell-Walsh-Wein Urology. 13th ed. Elsevier; 2026; Fletcher CDM. Diagnostic Histopathology of Tumors. 5th ed. Elsevier; 2021.
What's the difference between grading and staging?
The Gleason score and grade group tell your healthcare team whether your prostate cancer is growing slowly or quickly. The cancer's stage tells your healthcare team about the size of the cancer and whether it has spread beyond the prostate to lymph nodes or other parts of the body.
Cancer stages range from 1 to 4. A stage with a lower number typically means the cancer is smaller and only in the prostate and very likely to be cured. A stage with a higher number may mean a cure is less likely. Your prognosis depends on many factors, so talk about this with your healthcare team.
Cancer that starts in the prostate and spreads to another part of the body is known as metastatic prostate cancer. It's also known as stage 4 prostate cancer or advanced prostate cancer.
How is prostate cancer treated by grade group?
Your healthcare team considers many things besides the grade group when creating your prostate cancer treatment plan. The team considers the size of your cancer and whether it has spread. The team also considers your overall health and what you want and don't want from treatment.
Cancer that's found just in the prostate gland is treated differently from cancer that has spread to lymph nodes or to other parts of the body. Typically, treatments are combined to kill the cancer cells.
Treatment options by Gleason grade group may include some or all of the following. Talk with your healthcare team about your options.
Grade group 1
The lowest level of prostate cancer is very slow growing. It typically is not treated. This helps you avoid treatment you don't need and possible side effects. Instead, your healthcare team monitors the cancer during regular visits, usually every few months. This is known as active surveillance.
Regular visits may include a PSA blood test, a digital rectal exam, imaging tests or a prostate biopsy. The goal of active surveillance is to catch the cancer at the earliest stage of advancing and treat it at that time. Watchful waiting is similar to active surveillance but with fewer tests. It's typically an option for people who have poor health.
In some people, surgery to remove the prostate or radiation therapy may be options.
Grade group 2
If the number of grade 4 cells is low, active surveillance may be an option. This decision includes other factors such as your imaging test results, age, overall health and personal preference.
When the cancer is limited to only the prostate, treatment options may include radiation therapy, surgery to remove the prostate gland, or ablation therapy with hot and cold to hurt the cancer cells.
Grade group 3
Treatment options may include surgery to remove the prostate, radiation therapy or ablation therapy with hot and cold to hurt the cancer cells.
Grade group 4
Treatment options may include surgery to remove the prostate, radiation therapy or hormone therapy. Hormone therapy is medicine that shuts off your body from making sex hormones called androgens. Androgens encourage cancer cells to multiply. Stopping production of androgens causes the tumor to shrink. Hormone therapy can be used to treat advanced prostate cancer and some early-stage prostate cancers.
Grade group 5
Treatment options may include surgery to remove the prostate and lymph nodes radiation therapy, hormone therapy or chemotherapy.
What are the prognosis and survival rates for prostate cancer?
Prognosis tells you how likely it is that the cancer can be cured. Your healthcare team members can explain what they consider when thinking about your prognosis.
The cancer survival rate tells you the percentage of people who survive a certain type of cancer for a specific amount of time.
Survival rates take many things into consideration, such as the Gleason grade group, size of the tumor, the spread of the cancer, if any, and how well treatment is working. Talk with your healthcare team to learn more.
