What are the stages of nonmelanoma skin cancer?

The stage is based on the size of the tumor, how deeply into your skin it has grown, and if the cancer has spread beyond the tumor to the lymph nodes or other parts of your body. If you have squamous cell carcinoma, your doctor may also test lymph nodes near the tumor to see if the cancer has spread to them.

Stages are named using a combination of 0 or the Roman numerals I, II, III, and IV. Cancer with a lower stage will often be easier to treat and cure. The stages include:

• Stage 0. The cancer is only in the top layer of skin, called the epidermis. This is also called carcinoma in situ. In situ means the cancer has not spread into deeper tissues.

• Stage I. The tumor is 2 centimeters (cm) wide or smaller and has no more than one high-risk feature (see below). Cancer has not invaded the bone, and has not spread to the lymph nodes or other organs.

• Stage II. The tumor is larger than 2 cm or is any size and has 2 or more high-risk features (see below). Cancer has not invaded the bone, and has not spread to the lymph nodes or other organs.

• Stage III. The cancer has spread to bone by direct extension (such as the jaw or bones around the eye). Or it has spread to one nearby lymph node on the same side of the body as the tumor. The lymph node is not larger than 3 cm wide and the cancer has not spread to distant organs. Or, the cancer has spread to 1 lymph node on the same side of the body as the tumor, the lymph node is not larger than 3 cm wide, and 1 of these is true:

  • The tumor is not bigger than 2 cm and may have 1 high-risk feature

  • The tumor is bigger than 2 cm

  • The tumor is any size and has 2 or more high-risk features

• Stage IV. The cancer can be any size. It has grown into other bones, into more than one lymph node, or into a lymph node larger than 3 cm wide, or is in a lymph node on the other side of the body. Or, it has spread to other parts of the body.

Most nonmelanoma skin cancers are Stage 0 or Stage I. Stage III and IV are fairly rare.

High-risk features for nonmelanoma skin cancer

High-risk features are aspects that 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 (the dermis), or into the connective tissue beneath the dermis, called the subcutis (Clark level IV or V).

• The tumor has grown and spread along nerve pathways.

• The tumor began on an ear or on a part of the lip that has hair on it.

• The tumor cells look very abnormal under a microscope.

Talking with your healthcare provider

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