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Non-melanoma skin cancer

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Stages of non-melanoma skin cancer

Staging is a way of describing or classifying a cancer based on the extent of cancer in the body. The most common staging system for non-melanoma skin cancer is the TNM system. The International Union Against Cancer (UICC) uses the TNM system to describe the extent of many solid tumour cancers.

Basal cell carcinoma (BCC) rarely metastasizes to other organs, so it is not often staged (unless the tumour is very large).

 

Squamous cell carcinoma (SCC) has a slightly greater risk of spreading (although the risk is quite small), so the lymph nodes are usually examined. The growth pattern of SCC can vary from a slow-growing, locally invasive tumour to a fast-growing, widely invasive tumour.

The common staging system for non-melanoma skin cancer excludes tumours of the eyelid. The stages of eyelid tumours are described in the eye cancer chapter in the Canadian Cancer Encyclopedia. Merkel cell carcinoma also has its own staging system.

TNM

TNM stands for tumour, nodes, metastasis. TNM staging describes:

  • the size of the primary tumour
  • the number and location of any regional lymph nodes that have cancer cells in them
  • whether the cancer has spread or metastasized to another part of the body

Primary tumour (T)

TX

Primary tumour cannot be assessed

T0

No evidence of primary tumour

Tis

Carcinoma in situCarcinoma in situA very early stage of cancer in which tumour cells have not yet invaded surrounding tissues.

T1

Tumour is 2 cm or less in diameter with fewer than 2 high-risk features.

T2

Tumour is larger than 2 cm in diameter.

or

Tumour is any size with 2 or more high-risk features.

T3

Tumour invades the maxilla, mandible, orbit or temporal bone.

T4

Tumour invades the skeleton (axial or appendicular) or invades the skull base and is surrounding a nerve (perineural).

High-risk features for the primary tumour (T) staging

Depth or invasion

More than 2 mm thickness

Clark level IV or higher

Growth of tumour around a nerve (perineural invasion)

Anatomic location

Ear is the primary site

Upper lip is the primary site

Differentiation

Poorly differentiated or undifferentiated

Regional lymph nodes (N)

NX

Regional lymph nodes cannot be assessed

N0

No regional lymph node metastasis

N1

Metastasis in a single lymph node on the same side of the body as the tumour (ipsilateral) and the lymph node is 3 cm or less in diameter.

N2

Metastasis in a single ipsilateral lymph node and the lymph node is more than 3 cm, but not more than 6 cm, in diameter.

or

Metastasis in multiple ipsilateral lymph nodes with no lymph nodes more than 6 cm in diameter.

or

Metastasis in lymph nodes on both sides of the body (bilateral) or on the opposite side of the body as the tumour (contralateral) with no lymph nodes more than 6 cm in diameter.

N2a

Metastasis in a single ipsilateral lymph node and the lymph node is more than 3 cm, but not more than 6 cm, in diameter.

N2b

Metastasis in multiple ipsilateral lymph nodes and no lymph nodes are more than 6 cm in diameter.

N2c

Metastasis in bilateral or contralateral lymph nodes and no lymph nodes are more than 6 cm in diameter.

N3

Metastasis in a lymph node and the lymph node is more than 6 cm in diameter.

Distant metastasis (M)

M0

No distant metastasis

M1

Distant metastasis

Stage grouping for non-melanoma skin cancer

The UICC and the American Joint Committee on Cancer (AJCC) further group the TNM data into the stages listed in the table below.

UICC/AJCC staging – non-melanoma skin cancer
UICC/AJCCTNMExplanation

stage 0

Tis

N0

M0

carcinoma in situ (also called Bowen’s disease)

no cancer in regional lymph nodes or distant metastasis

stage I

T1

N0

M0

tumour is 2 cm or less in diameter with less than 2 high-risk features

no cancer in regional lymph nodes or distant metastasis

stage II

T2

N0

M0

tumour is greater than 2 cm in diameter

or

any size tumour with 2 or more high-risk features

no cancer in regional lymph nodes or distant metastasis

stage III

T3

N0

M0

tumour is any size and has spread to the jaw, eye socket or side of the skull

no cancer in lymph nodes

no distant metastasis

T1

N1

M0

tumour is 2 cm or less in diameter with less than 2 high-risk features

cancer has spread to one lymph node on same side of the body as the tumour and the lymph node is not larger than 3 cm

no distant metastasis

T2

N1

M0

tumour is larger than 2 cm

or

tumour is any size with 2 or more high-risk features

cancer has spread to one lymph node on same side of the body as the tumour and lymph node is not larger than 3 cm

no distant metastasis

T3

N1

M0

tumour is any size and has spread to jaw, eye socket or side of the skull

cancer has spread to one lymph node on same side of the body as the tumour and lymph node is not larger than 3 cm

no distant metastasis

stage IV

T1

N2

M0

tumour is 2 cm or less in diameter with less than 2 high-risk features

cancer has spread to one lymph node on the same side of the body as the tumour and the lymph node is more than 3 cm, but not more than 6 cm, in diameter

or

cancer has spread to more than one lymph node on one or both sides of the body and none of the lymph nodes are larger than 6 cm in diameter

no distant metastasis

T2

N2

M0

tumour is larger than 2 cm or tumour is any size with 2 or more high-risk features

cancer has spread to one lymph node on the same side of the body as the tumour and the lymph node is more than 3 cm, but not more than 6 cm, in diameter

or

cancer has spread to more than one lymph node on one or both sides of the body and none of the lymph nodes are larger than 6 cm in diameter

no distant metastasis

T3

N2

M0

tumour is any size and has spread to jaw, eye socket or side of the skull

cancer has spread to one lymph node on the same side of the body as the tumour and the lymph node is more than 3 cm, but not more than 6 cm, in diameter

or

cancer has spread to more than one lymph node on one or both sides of the body and none of the lymph nodes are larger than 6 cm in diameter

no distant metastasis

any T

N3

M0

tumour is any size and may have spread to the jaw, eye socket, skull, spine or ribs

metastasis in a lymph node, more than 6 cm in diameter

no distant metastasis

T4

any N

M0

tumour is any size and has spread to the base of the skull, spine or ribs

cancer may have spread to the lymph nodes

no distant metastasis

any T

any N

M1

tumour is any size and may have spread to the jaw, eye socket, skull, spine or ribs

cancer may have spread to the lymph nodes

cancer has spread to distant parts of the body

Recurrent non-melanoma skin cancer

Recurrent non-melanoma skin cancer means that the cancer has come back after it has been treated. It may recur in the same location as the original cancer or it may recur in another part of the body (metastatic non-melanoma skin cancer). BCC does not usually metastasize and SCC rarely metastasizes.

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Lusomé Founder and CEO Lara Smith Seeing my sister Erin – a young mother – struggle with the emotional blow and then the physical toll of cancer treatment made me want to do something to help women feel confident.

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