Nonmelanoma skin cancer usually develops slowly, invading and destroying nearby tissues. It may take months or years for basal cell or squamous cell carcinomas to develop. Because of this slow growth, skin cancer can often be detected and treated early in its development, increasing the chance for a cure.

• Basal cell carcinoma can invade normal skin tissue and damage deeper tissues, such as muscles and bones, and affect the appearance of the skin. Basal cell carcinoma very rarely spreads (metastasizes) to other parts of the body. If basal cell carcinoma comes back (recurs), it may grow faster and cause more tissue damage.
• Squamous cell carcinoma usually grows faster than basal cell carcinoma.² It often develops in injured or diseased skin areas.³ Squamous cell carcinoma can be disfiguring. Squamous cell carcinoma is more invasive than basal cell and can spread from the scalp, ears, eyelid, nose, or lip to other areas of the body. From 2% to 6% of squamous cell carcinomas spread to other parts of the body.⁴

Basal cell and squamous cell carcinomas are curable if they are detected and treated early. If skin cancer becomes more advanced, treatment will depend on the stage of cancer.

After you have one skin cancer, you are more likely to have another new skin cancer develop. Between 35% and 50% of people diagnosed with one basal cell carcinoma develop a new skin cancer within 5 years.³ People who have had nonmelanoma skin cancer may have an increased risk of developing other skin cancers, including melanoma.

Another type of skin condition with symptoms similar to nonmelanoma skin cancer is actinic keratosis. Although not a skin cancer, actinic keratosis may be a sign of sun-damaged skin and may lead to skin cancer. In some cases, an untreated actinic keratosis may develop into squamous cell carcinoma.