Stages and grades of skin cancer

The stage of a cancer tells you how big it is and whether it has spread. It helps your doctor decide which treatment you need.

The grade of a cancer tells you how much the cancer cells look like normal cells.

You might have tests to stage your cancer.  This depends on your type of skin cancer.

Most basal cell cancers (BCC) don't need staging because it's very rare for them to spread. You only need staging if your cancer is very large.

You are more likely to have staging if you have squamous cell skin cancers (SCC). This is because SCCs can spread, although this is still rare.

Doctors can use a numbers system or sometimes the TNM system (Tumour, Node, Metastases) to stage your cancer. 

Stage 0

Stage 0 is also called carcinoma in situ.

Carcinoma means there are cancer cells. In situ means the cells are still in the place where they started to develop. So the cells have started to turn into cancer, but they have not yet spread or grown into surrounding areas of the skin. 

Squamous cell carcinoma in situ is also called Bowen’s disease. Bowen's disease might develop into squamous cell carcinoma (SCC) if you don't have treatment. So your doctor may describe this stage as pre cancerous or pre malignant.

Stage 1

Stage 1 means the cancer is 2cm across or smaller.

Stage 2

Stage 2 means the cancer is larger than 2cm across, but no larger than 4cm.

Stage 3

Stage 3 can mean different things:

It can mean that your skin cancer hasn’t spread to any lymph nodes but it:

• is larger than 4cm across
• has grown into nearby bones causing minor damage
• has grown into the space around a nerve (perineural invasion)
• has grown below the layer of fat under the skin (subcutaneous tissue)

You can also have stage 3 skin cancer if your cancer is smaller than 4cm but it:

• has spread to a single lymph node on the same side of the body as your cancer, and the lymph node is 3cm or smaller

The cancer has not spread through the outside covering of the lymph nodes. 

Stage 4

Stage 4 skin cancer can mean your cancer is any size and has spread to one or more lymph nodes. And it means one or more of the following.

The cancer has:

• grown through the outside covering of one of the lymph nodes
• spread to more than one lymph node
• spread to only one lymph node which is larger than 3 cm and smaller than 6 cm
• spread to lymph nodes on the other side of your body to the skin cancer

Or it can mean your cancer has spread to:

• bone marrow or bone, including the bottom of the skull - and this has damaged the bone

Or your cancer has spread to:

• another part of your body, such as the lungs (distant spread)

Staging skin cancer affecting the eyelid

Doctors use a different staging system to stage skin cancers that start in the eyelid.

Stage 0

Stage 0 is also called carcinoma in situ.

Carcinoma means there are cancer cells. In situ means the cells are still in the place where they started to develop. So the cells have started to turn into cancer, but they have not yet spread or grown into surrounding areas. 

Stage 1

Stage 1 means the cancer has not spread into lymph nodes or to another part of the body. It is split into 2 groups – stage 1A and 1B.

Stage 1A means the cancer is 10mm across or smaller. It might have spread into the edge of the eyelid, or the tissue supporting the eyelid, or through the full thickness of the eyelid.

Stage 1B means the cancer is larger than 10mm across but no larger than 20mm. It hasn’t spread into the edge of the eyelid or the tissue supporting the eyelid.

Stage 2

Stage 2 means the cancer has not spread into lymph nodes or to another part of the body. It is split into 2 groups – stage 2A and 2B.

Stage 2A means different things:

• the cancer is larger than 10mm across but no larger than 20mm. It has spread into the edge of the eyelid, or the tissue supporting the eyelid, or through the full thickness of the eyelid.
• the cancer is larger than 20mm across but no larger than 30mm. It might have spread into the edge of the eyelid where the eyelashes are, or the tissue supporting the eyelid, or through the full thickness of the eyelid.

Stage 2B means the cancer is any size and has grown into nearby structures such as the eye, sinuses, tear ducts or brain.

Stage 3

Stage 3 means your cancer is any size. It might have spread into the edge of the eyelid, the tissue supporting the eyelid, through the full thickness of the eyelid, or into nearby structures.

It has spread to nearby lymph nodes. But it hasn’t spread to another part of your body. It is split into 2 groups – stage 3A and stage 3B.

Stage 3A means your cancer has spread to a single lymph node on the same side of the body as the cancer, and the lymph node is 3cm or smaller.

Stage 3B can mean different things. Your cancer has spread to:

• a single lymph node on the same side of the body as the cancer, and the lymph node is larger than 3cm
• lymph nodes on the other side of the body to your eyelid cancer, or to lymph nodes on both sides of your body

Stage 4

Stage 4 means your cancer has spread to another part of your body such as your lungs.

Grades

The grade of a cancer tells you how much the cancer cells look like normal cells.

The grade gives your doctor an idea of how the cancer might behave and what treatment you need.

The grades of cancer cells are from 1 to 3:

• grade 1 (low grade) look most like normal cells
• grade 2 look a bit like normal cells
• grade 3 (high grade) look very abnormal and not like normal cells

Treatment

 There are different treatment options for skin cancer. Your treatment depends on:

• the type of skin cancer
• how far it's grown or spread
• where the cancer is
• the stage of the cancer (if relevant)

Treatment might include:

• surgery
• radiotherapy
• photodynamic therapy
• immunotherapy 
• chemotherapy cream