Nonmelanoma 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 wart or mole. Overexposure to the sun's ultraviolet (UV) rays causes most nonmelanoma skin cancer.

Basal cell carcinoma and squamous cell carcinoma are the most common types of nonmelanoma 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 so more often than basal cell carcinoma.

It is important that nonmelanoma skin cancers be found early because treatment is very effective in the early stages. Nonmelanoma skin cancer is treated by removing the cancer with either surgery (excision) or freezing (cryotherapy). It rarely spreads (metastasizes) to other parts of the body.