BASAL CELL CARCINOMA
More than 80% of skin cancers are basal cell carcinomas. These cancers usually develop in sun-exposed areas, especially the head and neck, and tend to grow slowly. It’s very rare for a basal cell cancer to spread to other parts of the body. If left untreated, it can grow into nearby areas and invade other tissues beneath the skin. If not removed completely, basal cell carcinoma can recur in the same place on the skin. People who have had basal cell skin cancers are also more likely to get new ones in other places.
SQUAMOUS CELL CARCINOMA
About 10% of skin cancers are squamous cell carcinomas. These cancers also commonly appear on sun-exposed areas of the body such as the face, ears, neck, lips, and backs of the hands. They can also develop in scars or chronic skin sores elsewhere. Squamous cell cancers are more likely to grow into deeper layers of skin and spread to other parts of the body than basal cell cancers, although this is still uncommon.