Staging, grading and risk groups for prostate cancer

T describes the size of the tumour in the prostate gland.

N describes whether the cancer has spread to any lymph nodes (N). N0 means the cancer has not spread to the lymph nodes. Early prostate cancer is always N0. N1 means there is cancer in 1 or more lymph nodes close by.

M describes whether the cancer has spread to another part of the body. This is called metastatic cancer. M0 means the cancer has not spread to another part of the body. Early and locally advanced prostate cancer are always M0.

T1 – the tumour is within the prostate. It is too small to be felt during a digital rectal examination or seen on a scan. Your surgeon may find cancer if you have surgery for another reason – for example, an enlarged prostate. T1 tumours are divided into:

• T1a – the cancer is found in 5% or less of the tissue removed
• T1b – the cancer is found in more than 5% of the tissue removed
• T1c – the cancer is found by a needle biopsy, which was done because of a raised PSA level.

T2 – the tumour is within the prostate. A doctor can feel it when they do a digital rectal examination. The tumour can also be seen on a scan.

T1 and T2 tumours are not likely to affect the lymph nodes or spread to other parts of the body. Doctors call this early or localised prostate cancer.

T3 tumours have spread outside the prostate capsule. T3 tumours are divided into:

• T3a – the tumour has spread through the capsule on 1 or both sides of the prostate
• T3b – the cancer has spread to the seminal vesicles.

T4 tumours have spread outside the prostate and may be growing into tissues or organs close by. If the cancer has not spread to another part of the body, such as the bones, it is called locally advanced prostate cancer.

When the cancer has spread to another area, it is called advanced or metastatic prostate cancer.

T3 and T4 cancers are called locally advanced prostate cancer.

You can contact your doctor or specialist nurse about your TNM staging. They can explain it to you.

The Gleason score looks at the pattern of cancer cells in the prostate tissue, and how different they are to normal prostate cells.

There are 5 different patterns, graded from 1 to 5. Grades 1 and 2 look like normal prostate tissue. prostate cancer.  is Gleason grade 3, 4 and 5. Grade 5 is very different to normal tissue.

There may be more than 1 grade present in the biopsy. The doctor examines all the biopsy samples taken and identifies:

• the most common grade
• the highest other grade.

They add these together to give the Gleason score. For example, if the doctor finds the most common grade is 3 but the highest other grade seen in a sample is grade 4, then the Gleason score is 3 + 4 = 7.

The Grade Group is a number between 1 and 5. The lower the Grade Group, the less likely the cancer is to grow and spread.

Group 1 – Gleason score 6 (3+3)

The cancer cells look very similar to normal cells and are likely to grow very slowly, if at all.

Group 2 – Gleason score 7 (3+4)

Most of the cancer cells look like they will grow very slowly. Some may grow at a moderate rate.

Group 3 – Gleason score 7 (4+3)

Most of the cancer cells look like they will grow at a moderate rate. Some may grow very slowly.

Group 4 – Gleason score 8 (3+5, 4+4, 5+3)

The cancer cells look like they will grow at a moderately fast rate. Some may look like they will grow quickly.

Group 5 – Gleason scores 9 (4+5, 5+4) and 10 (5+5)

The cancer cells look like they will grow at a moderately fast rate or quickly.