Grade Groups are a way for doctors to explain how close prostate cancer cells are in appearance to cells without cancer. Prostate cancer grading shows how quickly these cells may grow or spread into other tissues.
Doctors can use the Gleason score and Grade Groups to assess how aggressive the prostate cancer is. They can use this information alongside the stage of the cancer to determine the best treatment plan.
This article explains how a cancer care team grades prostate cancer.
The Gleason score was the previous standard for measuring the aggressiveness of prostate cancer before doctors used a simplified scale, the Grade Groups.
The Gleason score typically ranges from 6 to 10. Scores 2 to 5 are possible but occur so rarely that they do not feature in official classifications.
Doctors
Cells in prostate cancer can be of different grades. The Gleason score adds the grades of the two Grade Groups that comprise the largest area in the biopsied tissue. For example, if prostate cancer has more grade 4 and 5 cells than any other, the doctor would add 4 and 5 to reach a Gleason score of 9.
However, the Gleason score does not present the whole picture of a person’s outlook. For example, the score shows that a biopsy contains a high number of a particular grade of cells. However, even a small number of grade 5 cells suggests a highly aggressive cancer.
Grade Groups have generally replaced the Gleason score for calculating prostate cancer’s aggressiveness. However, many physicians will report both Gleason scores and Grade Groups, according to the Prostate Cancer Foundation.
Since
The table below shows which Gleason scores feature in which Grade Groups and what this means for a person’s cancer.
| Grade Group | Gleason score | Risk level | Cell characteristics |
| 1 | 6 | low | The cells look like typical prostate gland cells. Grade Group 1 prostate cancer has a very low risk of rapid growth and may not grow at all. |
| 2 | 7 (with a majority of grade 3 cells) | moderate | Most cells look typical. Cancer is likely to be slow-growing. |
| 3 | 7 (with a majority of grade 4 cells) | moderate | Cells look less like typical prostate gland cells. These may grow moderately quickly. |
| 4 | 8 | high | Some cells are atypical, risking a moderate or rapid-growing cancer. |
| 5 | 9 and 10 | very high | The prostate cells are highly atypical. Rapid cancer growth is likely. |
Grade Group 1 has a low or very low risk. Grade Groups 2 and 3 have an intermediate risk, while Grade Groups 4 and 5 are high and very high risk.
Grades show how likely a cancer is to grow according to the appearance of its cells, whereas stages demonstrate how much a cancer has already grown or spread.
Doctors calculate the overall outlook of prostate cancer by working out the Grade Group along with other factors,
They will also look at the tumor, node, and metastasis (TNM) stage of the cancer. TNM refers to:
- the size of the tumor
- whether the prostate cancer has spread to nearby lymph nodes
- whether the prostate cancer has spread, or metastasized, to distant tissues
Learn more about what each stage of prostate cancer means.
A prostate biopsy is the definitive way to grade prostate cancer.
The results usually arrive in
If a doctor suspects prostate cancer, they may also request a blood test to assess PSA levels.
A doctor can advise on the tests they recommend and answer any questions a person may have.
Learn more about tests for prostate cancer.
Doctors can use cancer grading as part of how they recommend a course of treatment, along with the following factors:
- the amount of cancer in the prostate
- a person’s age and overall health
- an individual’s genes that may contribute to a more aggressive cancer
- a person’s preference for which treatment they would want
Prostate cancer can grow very slowly, and an individual may not need treatment if a doctor believes it will involve more risks than benefits. They
Learn more about treatments for prostate cancer by stage.
The Gleason score was the previous gold standard for grading prostate cancer. It rated prostate cell changes from 2 to 10, even though scores below 6 almost never occurred.
Over time, Grade Groups 1 to 5 started to replace the Gleason score. People may still see both on biopsy reports. Higher grades mean that there are more cells in a biopsy sample with abnormalities that suggest a rapidly growing, aggressive cancer.
Staging uses grading and other measures, such as prostate-specific antigen (PSA) levels and the size and spread of the tumor, to gauge how far prostate cancer has spread. Doctors may not need to treat low grade prostate cancer, but grading and staging can guide medical decisions on prostate cancer treatment.