Prostate cancer is divided into five Grade Groups based on the microscopic growth pattern and organisation of the cancerous glands. Grade Group 1 usually has the least aggressive pattern, while Grade Group 5 contains the most aggressive patterns.
Your grade helps your doctor estimate how quickly the cancer may grow or spread. It is considered alongside your PSA level, cancer stage, scan results and overall health. Your personal priorities also play an important role in choosing the most suitable treatment.
What Does Prostate Cancer Grade Mean?
The grade describes how the cancerous glands grow and are organised when examined under a microscope. More irregular and poorly organised growth patterns are generally associated with a greater likelihood of the cancer growing or spreading.
A specialist called a pathologist determines the grade by examining tissue from a prostate biopsy. The sample is carefully analysed to identify microscopic growth patterns and assign a Grade Group. This information guides further assessment and treatment decisions.
Grade and Stage Are Different
The grade reflects the microscopic growth pattern of the cancer and helps estimate how aggressively it may behave. The stage describes the size of the cancer, where it is located and whether it has spread beyond the prostate. These are separate but complementary parts of your assessment.
You can have a high-grade cancer that is still confined to the prostate. You can also have a lower-grade cancer that still needs careful monitoring or treatment. Both grade and stage are important when planning the most suitable approach for you.
What Is the Gleason Grading System?
The Gleason grading system describes the microscopic growth patterns of prostate cancer. When a needle-biopsy sample contains more than one pattern, the pathologist generally records the predominant pattern first and the highest-grade additional pattern second, then adds the two numbers to calculate the Gleason score.
The Gleason score is then converted into one of five Grade Groups. You may see both results in your pathology report because they describe the same grading information in different formats.
Understanding Gleason Scores and Grade Groups
| Grade Group | Gleason Score | General Meaning |
| Grade Group 1 | 3+3=6 | Contains only pattern 3 cancer and usually has the least aggressive appearance |
| Grade Group 2 | 3+4=7 | Mainly pattern 3 with a smaller amount of pattern 4 |
| Grade Group 3 | 4+3=7 | Mainly pattern 4 with a smaller amount of pattern 3 |
| Grade Group 4 | 4+4=8, 3+5=8 or 5+3=8 | Higher-grade cancer containing pattern 4 or pattern 5 |
| Grade Group 5 | 4+5=9, 5+4=9 or 5+5=10 | Contains the most aggressive microscopic patterns |
Why Does the Order of the Numbers Matter?
The order of the numbers shows which cancer pattern is predominant. Gleason 3+4=7 is Grade Group 2, whereas Gleason 4+3=7 is Grade Group 3. Although both scores add up to seven, 4+3 contains a greater proportion of pattern 4 cancer and is generally expected to behave more aggressively.
For needle biopsies, the second number reflects the highest-grade additional pattern identified. In a prostate removed during surgery, grading is generally based on the most common and second most common patterns, with a smaller higher-grade component recorded separately when appropriate.
What Is the Grade Group System?
The Grade Group system simplifies Gleason scores into five clear categories. It helps you understand cancer behaviour without assuming a Gleason score of 6 sits in the middle of a ten-point scale. This makes discussions more straightforward.
Grade Groups are now commonly used in routine clinical conversations. However, you may still see both Grade Group and Gleason score in your reports. Reports often include both because the Grade Group is easier to interpret, while the Gleason score shows the underlying combination of microscopic patterns.
Grade Group 1: Gleason 3+3=6
Grade Group 1 contains Gleason pattern 3 cancer and is the lowest Grade Group used in routine prostate cancer diagnosis. It usually has a lower risk of growth and spread than the other Grade Groups, although the stage, PSA level, MRI findings and amount of cancer remain important.
Active surveillance may be suitable when the cancer is localised and the overall Cambridge Prognostic Group supports monitoring. Grade Group 1 alone does not automatically mean that active surveillance is the most appropriate option.
Grade Group 2: Gleason 3+4=7
Grade Group 2 contains mainly pattern 3 cancer with a smaller amount of pattern 4. The percentage and type of pattern 4 may provide additional information about the likelihood of progression.
Some men with favourable localised disease may be offered active surveillance, while others may be advised to consider surgery or radiotherapy. The recommendation depends on the PSA level, stage, cancer extent, MRI findings, pathology features and general health.
Grade Group 3: Gleason 4+3=7
Grade Group 3 contains more pattern 4 cancer than pattern 3 cancer. Although the total Gleason score is also 7, it is usually more aggressive than Grade Group 2. This means the cancer may grow or spread more quickly.
Your specialist is more likely to recommend active treatment if the cancer is clinically significant. Options may include surgery or radiotherapy depending on your overall findings. Your PSA level, stage and general health are also considered.
Grade Group 4: Gleason Score 8
Grade Group 4 includes Gleason scores of 4+4=8, 3+5=8 and 5+3=8. These combinations contain high-grade microscopic patterns and are associated with a greater likelihood of growth, spread or recurrence than lower Grade Groups. However, the Grade Group does not show whether the cancer has already spread.
Active treatment is usually discussed when the cancer is localised or locally advanced and long-term cancer control is considered possible. Depending on the complete risk assessment, options may include radical prostatectomy in selected patients or radical radiotherapy, which is often combined with hormone therapy. The recommendation also depends on the stage, PSA level, scan findings, general health and personal priorities.
Grade Group 5: Gleason Scores 9 to 10
Grade Group 5 is the highest category and includes Gleason scores of 4+5=9, 5+4=9 and 5+5=10. These cancers contain the most abnormal microscopic patterns and have a higher risk of growth, spread and recurrence than cancers in the lower Grade Groups.
A high Grade Group does not mean that treatment cannot be effective. If the cancer is localised or locally advanced, treatment may involve radiotherapy with hormone therapy or, in selected cases, surgery as part of a broader treatment plan.
If the cancer is metastatic, treatment is usually based on hormone therapy combined with other systemic treatments. Radiotherapy may also be used in selected circumstances, but radical prostatectomy is not a routine treatment for metastatic disease.
Why Does the Lowest Gleason Score Start at 6?
Although Gleason patterns were originally numbered from 1 to 5, patterns 1 and 2 are not normally used in modern prostate needle-biopsy reporting. The lowest score usually assigned to prostate cancer on biopsy is therefore 3+3=6.
A score of 6 may appear to sit in the middle of a scale that ends at 10, but it represents Grade Group 1, the lowest category normally used for diagnosed prostate cancer. The Grade Group system helps make this distinction clearer.
How Is the Grade Found?
A prostate biopsy collects small tissue samples from different areas of the gland. A pathologist examines these samples to identify the Gleason patterns, assign a Grade Group and record information about the amount and location of cancer found.
MRI may identify suspicious areas and help guide targeted biopsy sampling, but it cannot determine the microscopic Grade Group by itself. Tissue must be examined by a pathologist to establish the cancer grade.
Can Different Biopsy Samples Have Different Grades?
Different biopsy samples can contain different Gleason patterns because prostate cancer may vary between separate areas of the gland. Your pathology report may provide a Gleason score or Grade Group for each positive core, biopsy site or MRI-targeted lesion and may also provide an overall assessment.
The scores are not simply averaged. Your multidisciplinary team will pay particular attention to the highest-grade finding while also considering how much cancer was found, which areas were involved, the percentage of pattern 4 or 5, your MRI findings, PSA level and clinical stage.
Can the Grade Differ After Surgery?
The Grade Group reported after radical prostatectomy may differ from the biopsy result because the pathologist can examine the whole prostate rather than a limited number of tissue samples. This is usually a difference in sampling and assessment rather than proof that the cancer suddenly changed during the period between biopsy and surgery.
The cancer may be upgraded if more aggressive patterns are found or downgraded if the overall findings are less concerning. The surgical pathology report also provides information about stage, margins, seminal vesicles and any removed lymph nodes.
Does Higher Grade Mean the Cancer Has Spread?
Not necessarily. Your Grade Group describes the cancer’s microscopic growth pattern and likely behaviour, not how far it has spread. Scans and staging tests are needed to assess its extent.
You can have a high-grade cancer that is still confined to the prostate. This means it may still be treatable with curative intent. However, higher-grade disease makes careful staging more important.
What Other Pathology Details Matter?
Your biopsy report may state the percentage of Gleason pattern 4 when Grade Group 2 or 3 cancer is present. It may also report whether invasive cribriform growth or intraductal carcinoma is present. These findings can be associated with a less favourable outlook and may affect whether active surveillance or active treatment is considered appropriate.
After surgery, the pathology report may describe whether cancer has extended beyond the prostate, reached a surgical margin, entered the seminal vesicles or spread to any removed lymph nodes. These findings are considered alongside your PSA results and Grade Group when estimating recurrence risk and planning follow-up.
How Are Grade, PSA and Stage Combined?
In the UK, your Gleason score or Grade Group, PSA level and clinical T stage are combined to place the cancer into one of five Cambridge Prognostic Groups, ranging from CPG 1 to CPG 5. A higher CPG generally represents a greater risk that the cancer will progress or affect long-term health.
The Cambridge Prognostic Group does not directly include every relevant factor, such as the amount of cancer in the biopsy, MRI details, general health or personal priorities. Your specialist will consider these additional findings alongside your CPG when discussing active surveillance, surgery, radiotherapy or other treatment options.
UK Guidance Note
Current NICE guidance uses the five-tier Cambridge Prognostic Group system to assess localised and locally advanced prostate cancer. The system combines Gleason score or Grade Group, PSA level and clinical T stage rather than relying on any one result.
NICE guideline NG131 remains the current guidance while a partial update is being developed. Until updated recommendations are published, your specialist should use the current guidance alongside your individual pathology, imaging, health and treatment preferences.
How Does the Grade Affect Treatment?
Lower-grade localised prostate cancer may be suitable for active surveillance when the complete risk assessment shows that immediate treatment is unlikely to provide enough benefit to outweigh its side effects. Monitoring normally involves PSA tests, clinical reviews, MRI and repeat biopsy when appropriate.
Higher Grade Groups are more likely to lead to discussion of surgery, radiotherapy, hormone therapy or combined treatment. The recommended approach depends on whether the cancer is localised, locally advanced or metastatic, so grade should never be used as the only treatment criterion.
Myth vs Fact
| Myth | Fact |
| A Gleason score of 6 is in the middle of the scale. | Gleason 3+3=6 is the lowest score usually assigned to prostate cancer in modern practice. |
| Gleason 3+4 and 4+3 mean the same thing. | They total seven, but 4+3 contains more pattern 4 cancer and belongs to a higher Grade Group. |
| A high grade means the cancer has already spread. | Grade describes the microscopic growth pattern, while stage describes the cancer’s location and extent. |
| Grade Group 1 never needs treatment. | Many cases can be monitored, but treatment decisions depend on the complete risk assessment. |
| MRI can determine the Grade Group. | MRI can identify suspicious areas, but microscopic grading requires examination of tissue. |
| The biopsy grade is always final. | The result may be upgraded or downgraded when the entire prostate is examined after surgery. |
| Grade alone decides treatment. | PSA, stage, scans, pathology findings, health and personal priorities are also considered. |
Key Takeaways
- Prostate cancer is divided into five Grade Groups.
- Grade Group 1 usually represents the least aggressive pattern, while Grade Group 5 represents the most aggressive.
- The Gleason score and Grade Group describe microscopic growth patterns, not how far the cancer has spread.
- Gleason 3+4=7 and Gleason 4+3=7 have different Grade Groups and expected behaviour.
- A biopsy provides an estimate because it samples only part of the prostate.
- The grade reported after surgery may differ when the whole prostate is examined.
- Grade, PSA level and T stage are combined to calculate the Cambridge Prognostic Group.
- Treatment decisions are based on the complete cancer assessment rather than grade alone.
Frequently Asked Questions
1. What do the different grades of prostate cancer mean?
The grade describes the microscopic growth pattern and organisation of your prostate cancer. Lower Grade Groups generally have less aggressive patterns, while higher Grade Groups are more likely to grow, spread or return after treatment.
2. How many Grade Groups are there in prostate cancer?
There are five Grade Groups, ranging from Grade Group 1 to Grade Group 5. Grade Group 1 is usually the least aggressive, while Grade Group 5 represents the most aggressive patterns.
3. What is the Gleason score in prostate cancer?
The Gleason score is calculated by adding two microscopic growth-pattern grades. In prostate core biopsies, these generally represent the predominant pattern and the highest-grade additional pattern found in the tissue.
4. Why does the order of Gleason numbers matter?
In a needle biopsy, the first number generally represents the predominant cancer pattern, while the second represents the highest-grade additional pattern identified. Gleason 4+3=7 contains more pattern 4 cancer than Gleason 3+4=7 and is therefore placed in the higher Grade Group 3.
5. What is Grade Group 1 prostate cancer?
Grade Group 1 usually corresponds to Gleason 3+3=6 and is the lowest category used in modern reporting. It often grows slowly, but suitability for active surveillance depends on the complete cancer assessment rather than Grade Group alone.
6. What does Grade Group 3 prostate cancer mean?
Grade Group 3 corresponds to Gleason 4+3=7 and contains more pattern 4 cancer than pattern 3 cancer. It is generally expected to behave more aggressively than Grade Group 2. Active treatment is therefore more commonly discussed, although the recommendation also depends on PSA, stage, imaging, general health and personal preferences.
7. Does a higher grade mean the cancer has spread?
No. The grade describes the cancer’s microscopic growth pattern and likely behaviour, not how far it has spread. A high-grade cancer can still be confined to the prostate.
8. Can the grade differ after prostate surgery?
Yes. The Grade Group reported after radical prostatectomy may differ from the biopsy result because the pathologist can examine the entire prostate rather than a limited number of tissue samples. This may reveal higher-grade or lower-grade patterns that were not accurately represented in the biopsy. It usually reflects more complete sampling rather than a sudden change in the cancer.
9. How does the grade affect your treatment options?
Lower Grade Groups are more likely to be considered for active surveillance when the cancer is localised and the overall risk is favourable. Higher Grade Groups more often require active treatment, but the recommendation also depends on PSA, stage, imaging, health and personal priorities.
10. What other factors are considered alongside the grade?
Your PSA level, cancer stage, scan results and overall health are all considered together with your grade. These factors help determine your overall risk and guide the most suitable treatment plan.
Final Thoughts: Understanding Your Prostate Cancer Grade and What It Means
Your prostate cancer grade provides important information about the microscopic growth pattern and likely behaviour of the cancer, but it is only one part of your diagnosis. Your Grade Group, Gleason score, PSA level, stage, imaging and other pathology findings should be considered together when assessing your risk and discussing treatment.
If you are looking for prostate cancer surgery in London, you can reach out to us to arrange a consultation and receive personalised advice about your diagnosis, treatment choices, and recovery.
References
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- Berney, D.M., Beltran, L., Fisher, G., North, B.V., Greenberg, D., Møller, H., Soosay, G., Scardino, P. and Cuzick, J. (2016) ‘Validation of a contemporary prostate cancer grading system using prostate cancer death as outcome’, British Journal of Cancer, 114(10), pp. 1078–1083. Available at: https://pubmed.ncbi.nlm.nih.gov/27100731/
- Epstein, J.I., Egevad, L., Amin, M.B., Delahunt, B., Srigley, J.R., Humphrey, P.A. et al. (2016) ‘The 2014 International Society of Urological Pathology consensus conference on Gleason grading of prostatic carcinoma: definition of grading patterns and proposal for a new grading system’, The American Journal of Surgical Pathology, 40(2), pp. 244–252. Available at: https://pubmed.ncbi.nlm.nih.gov/26492179/
- Epstein, J.I., Zelefsky, M.J., Sjoberg, D.D., Nelson, J.B., Egevad, L., Magi-Galluzzi, C. et al. (2016) ‘A contemporary prostate cancer grading system: a validated alternative to the Gleason score’, European Urology, 69(3), pp. 428–435. Available at: https://pubmed.ncbi.nlm.nih.gov/26166626/
- National Institute for Health and Care Excellence (2019) Prostate cancer: diagnosis and management. NICE guideline NG131. Last updated 15 December 2021 and last reviewed 13 August 2025. Available at: https://www.nice.org.uk/guidance/ng131
- NHS (2025) Treatment for prostate cancer. Last reviewed 31 July 2025. Available at: https://www.nhs.uk/conditions/prostate-cancer/treatment/
- Prostate Cancer UK (2023) What do my test results mean? Updated August 2023. Available at: https://prostatecanceruk.org/prostate-information-and-support/just-diagnosed/what-do-my-test-results-mean
- Prostate Cancer UK (2025) Prostate biopsy. Updated June 2025. Available at: https://prostatecanceruk.org/prostate-information-and-support/prostate-tests/prostate-biopsy
- van Leenders, G.J.L.H., van der Kwast, T.H., Grignon, D.J., Evans, A.J., Kristiansen, G., Kweldam, C.F. et al. (2020) ‘The 2019 International Society of Urological Pathology consensus conference on grading of prostatic carcinoma’, The American Journal of Surgical Pathology, 44(8), pp. e87–e99. Available at: https://pubmed.ncbi.nlm.nih.gov/32459716/
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