Basal cell skin cancer is the more common of the two types of nonmelanoma skin cancer, accounting for more than 90 percent of all skin cancers in the United States. It usually occurs on areas of the skin that have been in the sun.
Often this cancer appears as a small, fleshy bump or nodule on the head, neck, or hands. Sometimes the nodules are flat growths that appear on the trunk of the body.
Basal cell carcinoma is fairly easy to detect, grows very slowly (it may take months or years for a tumor to reach a diameter of a half-inch), and has an excellent record for successful treatment. The relative five-year survival rate is more than 99 percent when properly treated.
Basal cell cancers usually do not spread to other parts of the body but they sometimes spread to tissues around the cancer. They can extend below the skin to the bone and can cause considerable local damage as a result. In addition, nonmelanoma skin cancer puts people at a greater risk for developing additional cancers.
Squamous cell tumors also occur on areas of the skin that have been in the sun, often on the top of the nose, forehead, lower lip, and hands. They may also appear on areas of the skin that have been burned, exposed to chemicals, or had x-ray therapy.
Often this cancer appears as a firm red bump or scaly red patch. In a few percent of cases squamous cell tumors spread to other parts of the body, develop into masses, and metastasize. The overall five-year survival rate for patients with squamous cell carcinoma of the skin is more than 95 percent.