The Wrath of Skin Cancer
There’s no doubt that the sun is taking its toll on people. One in six Americans will suffer from skin cancer and every year that number rises by 4 percent according to the American Cancer Society. Of the 700,000 new cases that will be diagnosed in the U.S. this year, 80 percent of those will involve cells in the lower layer of the epidermis — otherwise known as basal cell carcinoma. An additional 130,000 skin cancers affect the pancake-shaped cells that form the skin’s upper layers; these are called squamous-cell cancers. The most serious of skin cancers called malignant melanoma is estimated to be diagnosed in 32,000 people this year and will kill at least 7,000.
Basal-cell cancer is the most common form of skin cancer, and also the most curable. Over 90 percent of basal cell carcinomas occur on the face, often at the side of the eye or on the nose. It starts as a small, flat nodule and grows slowly into a scaly area that does not heal and bleeds easily. Unless treated, the growth gradually invades and goes deeper into the surrounding tissues.
Fair-skinned persons over 50 are the most commonly affected. The incidence also increases significantly in those with outdoor occupations and living in sunny climates — in Queensland, Australia, over half the white population has basal cell carcinoma by age 75. Tumors can be destroyed by radiation therapy or surgery. Both of these methods usually give a complete cure. New tumors, however, develop in people who do not take adequate preventive measures.
The second most common form of skin cancer is squamous-cell cancer. It arises from flattened, scalelike cells in the skin, usually areas that have been exposed to strong sunlight for many years. This cancer is most common in pale-skinned, fair-haired people older than 60. The incidence is also higher in people whose work has exposed them to compounds such as arsenic, tar, coal, paraffin or heavy oils.
The tumor starts as a small, firm, painless lump or patch (usually on the lip, ear, or back of hand) and slowly enlarges, often resembling a wart or ulcer. If untreated, it may spread to other parts of the body and prove fatal. The tumor is removed in the same way as basal cell carcinomas. Treatment with anti-cancer drugs may also be necessary. Anyone who has had a squamous cell carcinoma should limit his or her exposure to sunlight.
The most serious of the three types of skin cancer is malignant melanoma. It occurs in the melanocytes — the cells that produce the pigment that colors the skin, hair, and the iris of the eyes.
Malignant melanomas account for 2 percent of all cancers and are most common in middle-aged and elderly people with pale skin who have been exposed to strong sunlight for many years.
The growth usually develops on exposed areas of skin, but may occur anywhere on the body, including under the nails and in the eye. The melanoma usually grows from an existing mole, which may enlarge, become lumpy, bleed, change color, develop a spreading black edge, turn into a scab, or begin to itch. Occasionally, a tumor may develop on normal skin. Because the tumor is highly malignant and often spreads to other parts of the body, early diagnosis is essential. Once the cancer has spread, it is almost always fatal.