Stages of non-melanoma skin cancer

Staging has been developed for non-melanoma skin cancer, but doctors do not use it often. This is because most non-melanoma skin cancers are found early and treated and don’t spread to other parts of the body. So staging is not needed. Doctors may classify non-melanoma skin cancer into risk groups instead of staging the cancer.

Staging describes or classifies a cancer based on how much cancer there is in the body and where it is when first diagnosed. This is often called the extent of cancer. Information from tests is used to find out the size of the tumour, the specific type of skin cancer, whether the cancer has spread from where it first started and where the cancer has spread. Your healthcare team may use the stage to plan treatment and estimate the outcome (your prognosis).

The staging system used for non-melanoma skin cancer is the TNM system. For non-melanoma skin cancer there are 5 stages – stage 0 followed by stages 1 to 4. Often the stages 1 to 4 are written as the Roman numerals I, II, III and IV. Generally, the higher the stage number, the more the cancer has spread. Talk to your doctor if you have questions about staging.

Some non-melanoma skin cancers are staged differently. The following types of non-melanoma skin cancer use different stage groupings, and some of these groupings are described below:

• non-melanoma skin cancer of the eyelid (see below for eyelid stages)
• non-melanoma skin cancer of the head and neck (see below for head and neck stages)
• perianal skin carcinoma (anal cancer)
• vulvar cancer
• penile cancer
• Merkel cell carcinoma

Find out more about staging cancer.

The following stages are used for non-melanoma skin cancers, including basal cell carcinoma and squamous cell carcinoma, except those of the eyelid and the head and neck.

The cancer cells are only in the top or outer layer of the skin (epidermis). Squamous cell carcinoma in situ is also called Bowen’s disease.

The tumour is 2 cm or smaller.

The tumour is larger than 2 cm but not more than 4 cm.

The cancer is stage 3 if any of the following apply:

• The tumour is larger than 4 cm.
• The tumour has slightly worn away nearby bone.
• The tumour has grown into or around nerves.
• The tumour has grown deep, past the fat under the skin.
• The cancer has spread to 1 lymph node that is 3 cm or smaller. The lymph node is on the same side of the body where the cancer started.

The cancer is stage 4A if any of the following apply:

• The cancer has spread to 1 lymph node that is larger than 3 cm but not more than 6 cm. The lymph node is on the same side of the body where the cancer started.

• The cancer has spread to many lymph nodes and none of the lymph nodes are larger than 6 cm. The lymph nodes are on the same side of the body where the cancer started.

• The cancer has spread to a lymph node that is larger than 6 cm.

The cancer has spread to other parts of the body (called distant metastasis), such as to the lungs, bone or lymph nodes on the opposite side of the body from where the cancer started. This is also called metastatic non-melanoma skin cancer.

The following stages are used for skin carcinoma of the eyelid, including basal cell carcinoma, squamous cell carcinoma and sebaceous gland carcinoma.

The cancer cells are only in the top or outer layer of the skin.

The tumour is 10 mm or smaller.

The tumour is larger than 10 mm but not more than 20 mm.

The tumour is larger than 10 mm but not more than 20 mm. The tumour has also grown into the fibrous layer of the eyelid (tarsal plate) or the edge of the eyelid (eyelid margin). The tumour may be the full thickness of the eyelid.

Or the tumour is larger than 20 mm but not more than 30 mm.

The tumour has grown into nearby areas of the face or eye, such as the lacrimal gland, eye socket (orbit) or sinuses.

The cancer has spread to 1 lymph node that is 3 cm or smaller. The lymph node is on the same side of the body where the cancer started.

The cancer has spread to 1 lymph node that is larger than 3 cm and on the same side of the body where the cancer started.

Or the cancer has spread to lymph nodes on the opposite side of the body from where the cancer started or both sides of the body.

The cancer has spread to other parts of the body, such as to the lungs or bone.

The following stages are used for skin carcinoma of the scalp, ears, lips and other parts of the face and neck.

The cancer cells are only in the top or outer layer of the skin.

The tumour is 2 cm or smaller.

The tumour is larger than 2 cm but not more than 4 cm.

The cancer is stage 3 if any of the following apply:

• The tumour is larger than 4 cm.
• The tumour has slightly worn away nearby bone.
• The tumour has grown into or around nerves.
• The tumour has grown deep, past the fat under the skin.
• The cancer has spread to 1 lymph node that is 3 cm or smaller. The lymph node is on the same side of the body where the cancer started.

The cancer has spread to 1 or more lymph nodes that are larger than 3 cm. The lymph nodes may be on the same side of the body where the cancer started, the opposite side of the body or both sides of the body.

Or the tumour has grown into bone, such as the skull, ribs, breastbone (sternum) or vertebrae. The cancer may have spread to 1 or more lymph nodes.

The cancer has spread to other parts of the body, such as to the lungs or other organs.

Recurrent non-melanoma skin cancer means that the cancer has come back after it has been treated. If it comes back in the same place that the cancer first started, it’s called local recurrence. If it comes back in tissues or lymph nodes close to where it first started, it’s called regional recurrence. In rare cases, it can recur in another part of the body. This is called distant metastasis or distant recurrence.