Most people with basal cell cancers do not need to have tests to find the stage of the cancer, as it is very rare for them to spread beyond the initial area of skin. Tests will only be done if the cancer is very large.

Although it is rare for squamous cell cancers to spread, tests to find the stage are more likely to be done for these because in some people they may spread.

A commonly used staging system is outlined below:

Stage 0
is also called carcinoma in situ. Carcinoma in situ means that cancer cells are present, but they are all contained in a small area in the top layer of skin (the epidermis) and have not started to spread or grow into deeper layers of skin. Squamous cell stage 0 is also called Bowen’s disease. If it is not treated, it can develop into a squamous cell skin cancer.

Stage 1
The cancer is less than 2cm across and has not spread

Stage 2
The cancer is more than 2cm across and has not spread

Stage 3
The cancer has spread into the tissues under the skin and possibly to nearby lymph nodes

Stage 4
The cancer has spread to another part of the body. This very rarely occurs with squamous or basal cell cancers of the skin.