What are the stages of nonmelanoma skin cancer?

The stage is based on the type of nonmelanoma skin cancer (basal or squamous cell), the size of the tumor, how deeply into your skin it has grown, and if the cancer has spread beyond the tumor to other parts of your body.

If you have basal cell carcinoma, stage is seldom needed because these cancers tend to be treated and cured before they have a chance to spread internally.

If you have squamous cell carcinoma, your healthcare provider may check the lymph nodes near the tumor to see if the cancer has spread to them.

Skin cancer staging is very complex. The TNM system from the American Joint Commission on Cancer is most often used to stage squamous (and sometimes basal) cell skin cancers of the head and neck (includes lip, face, scalp, and neck). Be sure to ask your healthcare provider to explain the stage of your cancer to you in a way you can understand.

The first step in staging is to find the value for each part of the TNM system. Here's what the letters stand for in the TNM system:

• T tells how far the main tumor has spread into the skin.

• N tells if the lymph nodes in the area of the original tumor have cancer in them.

• M tells if the cancer has spread ( metastasized) to distant organs in the body.

Numbers or letters after T, N, and M provide more details about each of these factors.

Stage groupings are determined by combining the T, N, and M values from the TNM system. These groupings give an overall description of your cancer. A stage grouping is listed as 0 or as a Roman numeral with a value of I through IV (1 through 4). Stage 0 is the earliest stage. The higher the number, the more advanced the cancer is. Letters and numbers can be used after the Roman numeral to give more details.

Most nonmelanoma skin cancers are Stage 0 or Stage I and can be easily treated. Stage III and IV are fairly rare.

High-risk features for nonmelanoma skin cancer

High-risk features can make a skin cancer harder to treat. These features include:

• The tumor is thicker than 2 millimeters.

• The tumor has spread into the lower layer of your skin, such as the connective tissue or fat under the dermis, called the subcutis.

• The tumor has grown and spread along nerve pathways.

• Cancer cells are in the blood vessels or lymph vessels outside the main tumor.

• The tumor began on an ear or lip.

• The cancer cells look very abnormal under a microscope.

• Being on immunosuppressive medicines (like those used to prevent organ transplant rejection)

Talking with your healthcare provider

When your cancer is staged, talk with your healthcare provider about what the stage means for you. Make sure to ask questions and talk about your concerns.