According to the American Academy of Dermatology, one in five Americans will develop some form of skin cancer in their lifetime. Skin cancer is the most common type of cancer in the U.S. Sun exposure is the leading cause of skin cancer, and people with fair skin and light eyes whose skin has a tendency to burn easily in the sun are most susceptible to the damaging effects of the sun's UV rays. Fortunately, most skin cancers can be detected in their early stages since skin tumors are more visible than tumors of the internal organs.
Types of skin cancer
Three types of cancers account for virtually 100% of skin cancers. The nonmelanomatous skin cancers include basal cell carcinoma and squamous cell carcinoma. Malignant melanoma is the third, and most deadly, type of skin cancer.
Basal cell carcinoma symptoms and signs
Basal cell carcinoma is by far the most common type of skin cancer, accounting for 80% of cases. These slow-growing tumors occur most commonly on areas of the body that are exposed to the sun and may take several forms. A raised, reddish, pearly nodule is the most common appearance of basal cell carcinoma, but it may also appear as a pink or red scar or area of irritated skin. Basal cell carcinomas metastasize (spread via the bloodstream or lymphatic channels) very rarely; instead, they grow invasively into surrounding tissues and can cause localized tissue destruction when not completely removed.
Squamous cell carcinoma
Squamous cell carcinoma is the second most common type of skin cancer, representing about 16% of all skin cancers. As with basal cell carcinoma, squamous cell carcinoma occurs most often in sun-exposed areas and in elderly people. Its appearance is similar to a chronic ulcerated area of the skin or a crusty or scaly skin lesion. Unlike basal cell carcinomas, squamous cell cancers metastasize to other parts of the body when they are not detected and removed at an early stage.
Melanoma symptoms and signs
The most dangerous skin cancer, melanoma, accounts for only about 1% or less of skin cancers, but it leads to the majority of deaths from skin cancer. This type of cancer often spreads to the lymph nodes and internal organs. While melanomas have a variety of physical appearances, they are most often pigmented lesions greater than 0.6 mm (about the size of a pencil eraser) in diameter. They may show a range of colors and generally have an irregularly-shaped, asymmetrical border. Melanoma can be cured by surgical removal if detected before spread to other organs has occurred. About 95% of melanomas can be cured when the cancer is limited to the outermost layer of the skin, but the prognosis is poor when melanoma has spread to other parts of the body.
Other forms of skin cancer
Early detection is essential for successful treatment of skin cancers. You should consult your doctor if you have any suspicious skin changes or lesions including:
- Moles that have changed in appearance, bleed, or become itchy
- Mew moles or sores
- Ulcers that do not heal
- Spreading of pigment beyond the borders of a mole or mark
- Moles that have grown or exhibit unusual changes
Avoidance of sun exposure and use of appropriate sunscreen products with broad spectrum coverage are the best ways to prevent all forms of skin cancer.
Quick GuideSkin Cancer Symptoms, Types, Images
"Skin Cancer Facts." American Cancer Society. <https://www.cancer.org/cancer/skin-cancer.html>.
"Skin Cancer Facts." Skin Cancer Foundation. Feb. 2, 2017. <http://www.skincancer.org/skin-cancer-information/skin-cancer-facts>.