The grade and stage of prostate cancer help determine the evolution of the disease. The grade refers to the degree of aggressiveness of the prostate cancer and can be assessed through the Gleason score. Cancer stage, meanwhile, refers to the degree of spread of cancer cells..

This article will cover the concept of prostate cancer stage, specifically the TNM classification system. The Gleason score has been addressed in a previous article.

The TNM classification system

The TNM method is the most commonly used system in Canada and around the world to classify the stages of prostate cancer.

The TNM classification is based on three components:

1. Primary Tumour
2. Regional Lymph Nodes
3. Metastasis

The “T” refers to the extent of the tumour in the prostate itself (local invasion). The “N” represents the degree of spread in pelvic lymph nodes (size and number of affected nodes). The “M” describes the presence or absence of cancer cells in distant organs (metastasis).

In the early stages, the cancer is confined to the prostate. In the intermediate stages of the disease, the cancer begins to extend beyond the prostate. In more advanced stages, the cancer cells spread to nearby lymph nodes (pelvic nodes) and distant structures and tissues (bones, etc.). The disease can later be generalized throughout the body.

The different stages according to the TNM system

Primary Tumour (T)

T1: The tumour is confined to the prostate and hardly detectable (discovered during PSA test)

T2: The tumour is local, but detectable during a rectal examination

T3: The tumour extends beyond the prostate

T4: The tumour has spread to surrounding structures and tissues (bladder neck, rectum, etc.)

Regional Lymph Nodes (N)

N0: There is no trace of a tumour in neighbouring lymph nodes

N1, N2, and N3: One or more regional lymph nodes are affected

Metastasis (M)

M0: There is no metastasis beyond the lymph nodes

M1: Presence of bone or distant metastasis

For example, a “T2 N0 M0” stage indicates that the cancer is confined to the prostate and there is no presence of cancer cells in pelvic lymph nodes or distant prostatic tissue.

Le choix et l’ordre des traitements d’un cancer de la prostate dépendent notamment de l’étendue du cancer au moment du diagnostic et de son évolution potentielle.

You have questions? Speak to one of our health professionals.

Contact our toll-free 24/7 line at 1 855 899 – 2873

Join us and attend our conference Monday, April 27, 2015 from 19h to 21h. Click here.