Skin cancer is the most prevalent of all cancers. Estimates vary on its occurrence but it is estimated that approximately 700,000 Americans develop skin cancer every year.
Sun avoidance is the best defense against skin cancer.
The principal cause of skin cancer is almost universally accepted by medical experts to be overexposure to sunlight, especially when it results in sunburn and blistering. Other less important factors would include: repeated medical and industrial x-ray exposure; scarring from diseases or burns; occupational exposure to such compounds as coal and arsenic, and family history.
Prevention is a matter of guarding the skin against the known causes. Since the sun and its ultraviolet rays would seem to be the main culprit, the most effective preventive method is sun avoidance. Limit the exposure of the skin to harmful rays by covering up and using sunscreens with at least a 15 SPF rating.
Early detection is the surest way to a cure.
It is a simple routine to inspect your body for any skin changes. Actinic keratosis and each of the skin cancers depicted in the following pages can be readily detected. If any growth, moles, sore or discoloration appears suddenly or begins to change, see your dermatologist.
Precancerous skin conditions
Be alert for a precancerous lesion called actinic keratosis. These small scaly spots are most commonly found on the face and back of the hands in fair-skinned individuals who have had significant sun exposure. If they are not treated, some of them may become skin cancer, requiring more extensive treatment. If they are diagnosed in the early stages, actinic keratosis can be removed By applying a topical form of chemotherapy or by other outpatient procedures.
There are three forms of skin cancer:
Basal cell carcinoma
This tumor of the skin usually appears as a small, fleshy bump or nodule on the head, neck and hands. Occasionally these nodules may appear on the trunk of the body, usually as flat growths. Basal cell carcinomas seldom occur in dark-skinned persons; they are the most common skin cancers found in Caucasians. It has been found that people who have this cancer frequently have light hair, eyes and complexions, and they don't tan easily. These tumors don't spread quickly. It may take many months or years for one to reach a diameter of one half inch. Untreated, the cancer will begin to bleed, crust over, then repeat the cycle.
Although this type of cancer rarely metastasizes (spread to other parts of the body), it can extend below the skin to the bone and cause considerable local damage.
Squamous cell carcinoma
These tumors may appear as nodules or as red, scaly patches. Squamous cell carcinoma is the second most common skin cancer found in Caucasians. It typically is found on the rim of the ear, the face, the lips and mouth. It is rarely found on dark-skinned persons. This cancer will develop into large masses. Unlike basal cell carcinoma, it can metastasize. It is estimated that there are 2,300 deaths from non-melanoma skin cancers every year.
Malignant melanoma
It is projected that this most virulent of all skin cancers develops on the skin of 32,000 Americans annually. And every year an estimated 6,800 Americans will die from melanoma. It is important to note that the death rate is at last declining, because patients are seeking help earlier. Melanoma, like its less aggressive cousins, basal cell and squamous cell carcinomas, is almost always curable in its early stages.
Melanoma has its beginnings in melanocytes, the skin cells that produce the dark protective pigment called melanin. It is melanin that is responsible for suntanned skin, acting as partial protection against sun. Melanoma cells usually continue to produce melanin, which accounts for the cancers appearing in mixed shades of tan, brown and black. Melanoma has a tendency to spread, making it essential to treat.
Melanoma may suddenly appear without warning but it may also begin in or near a mole or other dark spot in the skin. For that reason it is important that we know the location and appearance of the moles on our bodies so any change will be noticed.
Excessive exposure to the sun, as with the other skin cancers, is accepted as a cause of melanoma, especially among light-skinned people. Heredity may play a part, and also atypical moles, which may run in families, can serve as markers, identifying the person as being at higher risk for developing melanoma there or elsewhere in the skin.
Dark brown or black skin is not a Guarantee against melanoma. Black people can develop this cancer, especially on the palms of the hands, soles of the feet, under nails, or in the mouth.
Other warning signs include: changes in the surface of a mole; scaliness, oozing, bleeding or the appearance of a bump or nodule; spread of pigment from the border into surrounding skin; and change in sensation including itchiness, tenderness, or pain.
How skin cancer is treated
If a laboratory test reveals that an area of the skin is cancerous, the dermatologist has an array of procedures to choose from, dependent on the needs of the individual patient. In the treatment of any of the skin cancers, early detection and removal is the best defense.
Fortunately, skin cancers are relatively easy to detect and most can be cured. Even malignant melanoma, if caught in its early stages, can be treated successfully.
Dermatologists recommend that one helpful way to guard against melanoma/skin cancer is to do periodic self-examinations. Get familiar with your skin and your own pattern of moles, freckles and "beauty marks." Be alert to changes in the number, size, and shape and color of pigmented areas.
© 1994 American Academy of Dermatology
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