Prostate Cancer: Grades and Stages
Stay up to date on research and information
Sign Up for FORCE NewslettersGrades and Stages of Cancer
Measuring the grade and of cancer helps doctors decide how to treat it.
Grades, Gleason score and grade groups
The grade of a cancer helps doctors predict how quickly the cancer is likely to grow and spread. This information helps doctors make decisions on how best to treat it. Doctors use two scales, the Gleason score and the grade group to measure and report the grade of cancer.
What is a Gleason score?
The Gleason score is based on how abnormal the cells appear in the two largest areas of the tumor. The pathologist assigns a score of 1-5 for each area and adds them together for the Gleason score. Although Gleason scores can range from 2-10, most cancers will be scored as 6 or higher. The higher the score, the more abnormal and aggressive the cells appear. Using this measuring system, doctors label cancers as low, medium or high grade.
What is a grade group?
Doctors now use an updated "grade group" scoring system, which can give them a better idea of how aggressive a cancer is likely to be. The grade group system uses the two Gleason score numbers to divide cancers into five separate categories.
Participate in Research
cancer Gleason scores and grade groups
Gleason Score |
Grade Group |
Description |
Gleason score 6 |
Grade group 1 |
These are considered low grade prostate cancer. They tend to be slow-growing and less likely to spread. |
Gleason score 7 |
Grade group 2 |
Grade group 2 cancers have a combined Gleason score of 7 (3+4). This means that larger portion of the cancer is Gleason score 3 than Gleason score 4. These are considered intermediate grade cancers. Grade group 2 cancers have a better outlook than grade group 3 cancers. Even though the total Gleason score is the same for both groups, grade group 2 has less aggressive cancer present. |
Gleason score 7 |
Grade group 3 |
Grade group 3 cancers have a combined Gleason score of 7 (4+3). This means that a larger portion of the cancer is Gleason score 4 than Gleason score 3. These are considered intermediate grade cancers. Grade group 3 cancers are considered more aggressive than grade group 2 cancers, even though the total Gleason score is the same for both groups. |
Gleason score 8 |
Grade group 4 |
These are high grade prostate cancer. These are more aggressive and faster-growing cancers. For this reason, they are also known as high risk prostate cancers. |
Gleason score 9-10 |
Grade group 5 |
These are high-grade prostate cancer. These are more aggressive and faster-growing cancers. For this reason, they are also known as very high risk cancers. |
What are the stages of cancer?
The refers to whether the cancer has spread beyond the , and if it has, the location in the body where it has spread. Doctors use the following information to prostate cancer:
- size of the tumor
- whether the cancer has spread to nearby
- the presence or absence of spread beyond the and ()
- levels at the time of diagnosis
- Gleason score
Stage |
Description |
Stage 1 |
This stage is contained to the prostate, has a Gleason score of 6 or below and a PSA level of less than 10. |
Stage 2 |
The cancer is more advanced but has not spread beyond the prostate. |
Stage 3 |
The cancer extends beyond the prostate but has not spread to lymph nodes. |
Stage 4 or metastatic |
The cancer has spread to another part of the body outside of the prostate. Common areas of spread include the bladder, rectum, lymph nodes or bones. |
Additional tests for
After grading and , additional tests or imaging may be done to check for cancer spread, though these are not required for all newly diagnosed cancer.
Additional tests are run if:
- levels are high.
- The Gleason score is high.
- The cancer is large.
- The cancer has spread to or beyond.
The tests may include:
- Computed tomography (CT) scans of the abdomen and pelvis
- Bone scans
- Magnetic resonance imaging () of the pelvis
- Positron emission tomography (PET) scans
- Pelvic lymph node dissection (PLND)
Additional tests may be performed on blood or tissue to help guide treatment. For some patients, these tests may help guide the choice of or .