What is TNM?

TNM is a system for classifying malignant tumours!

It is a cancer staging system, which describes the extent of a person's cancer!

Most medical facilities use this system as their main method for cancer reporting1!

Most types of cancer have TNM designations, but some do not1!

1. National Cancer Institute, Cancer Staging, 2010

How does the TNM system work?

The 3 parameters of the TNM system1:

T = extent of the tumour

N = the extent of spread to the lymph nodes

M = presence of distant metastases

A number is added to each letter

to indicate1:

the size or extent of the primary tumour

the extent of cancer spread

1. National Cancer Institute, Cancer Staging, 2010

T = extent of primary tumour

organlocal tissues

T0 T1 T2 T3

T is classified as follows:1

Tx: Primary tumour cannot be evaluated | T0: No evidence of primary tumour

Tis: Carcinoma in situ (CIS)2 | T1, T2, T3, T4: Size and/or extent of the primary tumour

1. National Cancer Institute, Cancer Staging, 20102. CIS – abnormal cells are present but have not spread to neighbouring tissue; although not cancer, CIS

may become cancer and is sometimes called pre-invasive cancer

N = extent of spread to lymph nodes

distant nodes

local nodes

N0

N is classified as follows1:

Nx: Regional lymph nodes cannot be evaluated | N0: No local lymph node involvement

N1: Tumour has spread to local lymph nodes | N2, N3: Involvement of local and distant lymph nodes (number of lymph nodes and/or extent of spread)

1. National Cancer Institute, Cancer Staging, 2010

N1 N2

M0

M = presence of distant metastases

M is classified as follows1:

Mx: Distant metastasis cannot be evaluated | M0: No distant metastasis

M1: Distant metastasis is present

1. National Cancer Institute, Cancer Staging, 2010

bone

lung

liver

M1 Mx

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