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The Sun and Your Skin

Skin Cancer

Did you know your lifetime chance of getting skin cancer is 1 in 5? Approximately 90% of skin cancers are caused by the sun. In this section, you will learn about skin cancer and the need to protect yourself from the harmful rays of the sun.

In 2012, more than two million Americans were diagnosed with skin cancer. It is the most common type of cancer, and accounts for nearly half of all cancers in the United States. An estimated 12,000 Americans (more than one per hour) died from the disease.

There are three common types of skin cancer: Melanoma, Squamous cell carcinoma, and Basal cell carcinoma.

Each of these cancers is named for the type of skin cell from which it arises. Melanoma is a malignancy of the skin's pigment-producing cells or melanocytes. Squamous cell carcinoma is a malignancy of the cells of the middle or upper epidermis, while basal cell carcinoma occurs when the cells at the base of the epidermis turn malignant.

Diagram of skin cells and cancerous cells


The incidence of malignant melanoma, the most deadly form of skin cancer, has been increasing faster than any other type of cancer and has doubled since 1973. In 2012, it was estimated that there were 75,000 new cases of melanoma and 9,000 deaths in the United States.1

Melanoma is less common than the other two types of skin cancer, but is far more serious. It is curable in its early stages, but because of its potential to metastasize (spread to other regions of the body), early detection and treatment is crucial.

Melanoma is characterized by the uncontrolled growth of pigment-producing cells (melanocytes). Melanomas are found most frequently on the upper backs of men and women or on the legs of women, but can occur anywhere on the body including melanoma of the eye and parts of the body that have not been exposed to the sun.

Melanoma most commonly has the appearance of an unusual mole. It frequently exhibits the ABCDE's of:

  • Asymmetry
  • Border irregularity
  • Coloration that appears dark or in multiple shades
  • Diameter the size of a pencil eraser or larger
  • Evolving

Any pigmented skin lesion that is new, enlarges, changes shape, darkens or looks odd compared to typical moles, is cause for concern. Melanoma can appear on previously normal skin, or can develop in a pre-existing mole. Melanomas may suddenly appear without warning.

Non-Melanoma Skin Cancers

Ask your doctor if you have any cause for concern about your skin.

Basal and squamous cell skin cancers are non-melanoma skin cancers. They are very treatable and not generally life-threatening. Basal and squamous cells are located at the base of the outer layer of the skin. Most non-melanoma skin cancers develop on sun-exposed areas of the body, like the face, ear, neck, lips, and the backs of the hands. They can grow fast or slow, but rarely spread to other parts of the body. Often people who have had one non-melanoma skin cancer will develop a new one within five years. They can be removed easily and tend not to spread if treated early.

Squamous cell carcinoma is not as aggressive as melanoma. Cure rates are in excess of 95% when the tumor is detected and treated early. Chronic overexposure to the sun, as might occur with outdoor recreation or employment is a major cause. Actinic keratosis (AK) is a very common skin lesion which is now recognized as the earliest stage in the development of skin cancer. Squamous cell carcinoma usually appears as a reddish-colored firm lump or plaque with a scaly surface. Actinic keratosis (a precursor of squamous cell carcinoma) is a small pinkish scaly patch. Left untreated, these lesions can progress to squamous cell carcinoma.

Basal cell carcinoma is the most common and least aggressive type of skin cancer. However, it can be quite destructive and has the potential to spread if left untreated. Basal cell carcinoma, in its classic form, is a small bump with a translucent quality. It is somewhat red due to enlarged "bloodshot" vessels on its surface. As it grows larger, the surface often ulcerates or forms a scab.

If you are concerned about any suspicious moles on your body or if any of your moles exhibit any of the above signs of skin cancer, please consult a medical doctor or dermatologist.

Skin cancer is largely preventable by avoiding overexposure to UV radiation. Most people attain up to 25% of their lifetime sun exposure before their 18th birthday,2 and just two or more blistering sunburns during adolescence nearly doubles the risk of melanoma.3

1: American Cancer Society.
2: Godar, DE: UV doses of young adults. Photochem and Photobiol. 2003;77(4):453-457.
3: Weinstock MA, Colditz GA, Willett WC, et al. Pediatrics. 1989;84(2):199-204.