Summer's the season for fun in the sun—but also for skin cancer.
Of the three main types of skin cancer, melanoma is most deadly,
and basal cell, most common. Squamous cell cancer falls in
between. It's three times as common as melanoma (some 200,000 new
cases each year versus 62,000). Though not as common as basal
cell (about one million new cases a year), squamous cell is more
serious because it is likely to spread (metastasize). Treated
early, the cure rate is over 90%, but metastases occur in 1%–5%
of cases. After it has metastasized, it's very difficult to
Squamous cell cancer involves the runaway growth of
keratinocytes, cells in the outermost layer of skin, which
produce the protein keratin. Squamous means scaly; in 60%–80% of
cases, the lesions emerge on or near scaly patches called actinic
keratoses that develop from sun-damaged skin.
Typically, such lesions are hard (from the keratin),
well-defined, and occasionally crusty. Some you might mistake for
a wart, only flatter. And there are those that are soft and
fleshy. The pictures elsewhere on this Web page will give you an
idea of what some of them look like.
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