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TNM Staging

Find out about tumour, node and metastasis (TNM) staging and treatment.

Your scans will give some information about the stage of your cancer. But your doctor may not be able to tell you the exact stage until you have surgery.

The TNM staging system is the most common way that doctors stage prostate cancer. TNM stands for Tumour, Node, Metastasis.

Doctors may also use a number staging system.

Or your doctor might describe your cancer as localised, locally advanced or advanced.

Tumour (T)

Tumour describes the size of the tumour (area of cancer). This is a simplified description of the T stage.

There are 4 main stages of cancer size in prostate cancer – T1 to T4.

TX means the main cancer (primary) can’t be assessed.

T0 means there is no sign of cancer.

T1

T1 means the cancer is too small to be seen on a scan, or felt during examination of the prostate.
It’s divided into T1a, T1b and T1c.

T1a and T1b

The surgeon unexpectedly finds T1a and T1b cancers during surgery for other reasons. The cancer is in less than 5% of the removed tissue (T1a) or more than 5% of the removed tissue (T1b).

T1c cancers are found by biopsy, for example after a raised PSA level.

T2

T2 means the cancer is completely inside the prostate gland. It’s divided into T2a, T2b and T2c.

T2a means the cancer is in only half of one side of the prostate gland.

T2b means the cancer is in more than half of one side of the prostate gland.

T2c means the cancer is in both sides but is still inside the prostate gland.

T3

T3 means the cancer has broken through the capsule (covering) of the prostate gland. It’s divided into T3a and T3b.

T3a means the cancer has broken through the capsule (covering) of the prostate gland.

T3b means the cancer has spread into the tubes that carry semen (seminal vesicles).

Diagram showing TNM stages for prostate cancer.jpg

T4

T4 means the cancer has spread into other body organs nearby, such as the back passage, bladder, or the pelvic wall.

Diagram of the prostate showing a T4 sized tumour

Node (N)

Node (N) describes whether the cancer has spread to the lymph nodes.

  • NX means that the lymph nodes can’t be assessed
  • N0 means that the nearby lymph nodes don’t contain cancer cells
  • N1 means there are cancer cells in lymph nodes near the prostate
Diagram showing the lymph nodes around the prostate

Metastasis (M)

Metastasis (M) describes whether the cancer has spread to a different part of the body.

There are 2 stages of metastasis – M0 and M1.

M0 means the cancer hasn’t spread to other organs.

M1 means the cancer has spread to other parts of the body outside the pelvis. It is split into M1a, M1b and M1c.

M1a means there are cancer cells in lymph nodes outside the pelvis

M1b means there are cancer cells in the bone

M1c means there are cancer cells in other places

Diagram showing metastasis of prostate cancer

Treatment

The stage of your cancer helps your doctor to decide which treatment you need. Treatment also depends on:
  • what the cancer cells look like under the microscope (Gleason score)
  • your PSA blood test level
  • your type of cancer (the type of cells the cancer started in)
  • your age and general health
  • how you feel about what the treatments involve and the side effects

You might not have treatment straight away. Sometimes your doctor monitors your cancer and starts treatment if the cancer begins to grow. Depending on your situation, they may call this:

  • active surveillance
  • watchful waiting
If you have treatment this might include:
  • surgery to remove your prostate
  • external radiotherapy
  • internal radiotherapy (brachytherapy)
  • hormone therapy
  • high frequency ultrasound therapy (HIFU) as part of a clinical trial
  • cryotherapy as part of a clinical trial
  • chemotherapy
  • symptom control treatment
Last reviewed: 
06 Jul 2016
  • AJCC Cancer Staging Manual (7th Edition)

    S Edge and others. Springer. 2011

  • Cancer of the prostate: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

    C Parker and others. Annals of Oncology, 2015. Vol 26 (suppl 5): v69-v77

  • Prostate cancer: diagnosis and management

    National Institute for Health and Care Excellence (NICE) guidelines, January 2014.

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