Non-melanoma skin cancer usually appears as a change in the skin, such as a growth, an irritation or sore that does not heal, or a change in a mole or a skin growth. Overexposure to the sun's ultraviolet (UV) rays causes most non-melanoma skin cancer.

Basal cell carcinoma and squamous cell carcinoma are the most common types of non-melanoma skin cancer.

• Basal cell skin cancer accounts for most skin cancers. It is a slow-growing cancer that seldom spreads to other parts of the body.
• Squamous cell skin cancer is less common. It also rarely spreads. But it does spread more often than basal cell carcinoma.

These cancers may cause extensive damage, and early therapy is more likely to be effective. Non-melanoma skin cancer is often treated by removing the cancer with surgery. Other treatments include radiation, medicines that are put on the skin (topical therapies), and photodynamic therapy (PDT).