Word: squamous
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Dates: during 1990-1999
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SKIN-CANCER RISE Among Caucasians, the incidence of squamous-cell carcinoma is climbing faster than expected. Since the mid-'80s, rates have doubled in women and gone up one-quarter...
...will involve cells found in the lower layers of the epidermis. These so-called basal-cell cancers develop slowly, spread rarely and are nearly 100% curable. An additional 130,000 skin cancers affect the pancake-shaped cells that form the skin's upper layers. Although highly treatable, these squamous-cell carcinomas grow faster than basal-cell tumors and annually kill 2,300 Americans. Malignant melanoma, which ravages the skin's pigment-producing cells, is the most unforgiving: it will strike twice as many Americans in 1993 as in 1980. Nearly 7,000 will die this year...
...evidence gathered from animal experiments and epidemiological surveys points to the high-energy, shorter-wave ultraviolet-B portion of the sun's radiation as the main culprit in causing basal- and squamous-cell cancer. (Sunburns are also caused by UV-B radiation, wrinkles by the weaker UV-A part of the spectrum.) Since no animals other than humans and opossums suffer from malignant melanoma, researchers still do not know exactly what causes that more deadly disease. Most dermatologists have long assumed that sunburn-causing UV-B must be a greater threat than UV-A. As a result, sunscreen manufacturers originally...
...skin's dynamic outer layer, or epidermis, serves as the staging ground for all three of the major skin cancers. Both basal-cell and squamous-cell carcinomas arise from the most common skin cells, the keratinocytes, which form at the base of the epidermis and work their way toward the surface. Near the base, they are plump and are called basal cells. But as they move outward, they flatten to become the squamous cells that form the skin's tough, protective surface. Melanomas spring from melanocytes, cells that produce pigment...
...Squamous-cell carcinomas also develop from keratoses on long-exposed areas of the skin, affecting about 100,000 Americans each year. They take the form of red or pink warty growths that may scale or open in the center and ooze. Squamous tumors are more dangerous than basals; they grow more rapidly and can metastasize, sometimes with fatal results...