skin cancer
The different types, and
what to look for when examining your own skin
By Robyn E. Glaesser, M.D.
There are three
major types of skin cancer: basal cell carcinoma,
squamous cell carcinoma and malignant melanoma. With
an estimated annual incidence in the United States
of 900,000, the most common type of skin cancer (and
all cancer, for that matter) is basal cell carcinoma
(BCC). The lifetime risk of developing BCC for Caucasian
people is about 35% in men and 25% in women. BCC
is thought to arise from hair follicle stem cells
that lie below the surface of the skin. It typically
occurs in areas of chronic sun exposure and often
has as a waxy or pearly appearance. Although BCC
is usually slow growing and very rarely spreads (metastasizes)
to other organs of the body, if left untreated, it
can be quite disfiguring. Fortunately, the prognosis
is excellent with proper therapy. Treatment typically
involves either surgical excision or removal via
electrodessication and curettage (a simple “scrape
and burn” technique).
Squamous cell carcinoma
(SCC), the second most common type of skin cancer,
afflicts about 200,000 Americans per year. It arises
from the epidermis, the outermost layer of the skin,
and like BCC, tends to occur on sun-exposed areas.
The rim of the ear and the lower lip are particularly
vulnerable to development of SCC. These cancers often
present as wart-like growth that crust and occasionally
bleed. Although most are diagnosed early enough to
successfully treat with surgical excision or electrodessication
and curettage, untreated SCC can metastasize to distant
tissues and can be fatal.
Malignant melanoma
is the most serious type of skin cancer. Over 50,000
new cases are reported each year, and the incidence
is rising more rapidly than any other type of cancer.
The tumor originates in melanocytes, the cells that
give skin, hair and eyes their pigment. Therefore,
most melanomas are black or brown in color, but they
can rarely be pink, purple, red or skin-colored. They
tend to be flat, with irregularly-shaped borders. If
diagnosed and surgically removed early, the cure rate
approaches 100%. As the cancer advances, the risk of
metastasis to other organs increases dramatically.
Once this occurs, treatment is difficult, and many
cases result in death.
The most important
thing you can do to limit your risk of developing one
of these types of skin cancer is to protect your skin
from the sun by avoiding sun exposure from 10:00 am
to 4:00 pm, wearing sun protective clothing and using
sunscreen routinely. It is also important to examine
your skin monthly for any suspicious growths and new
or changing moles. If you notice anything unusual,
see your dermatologist for an evaluation. If you do
in fact have a skin cancer, it will in all likelihood,
be completely curable.
About the
author
Doctor Robyn E. Glaesser is a practicing Dermatologist
at Ironwood Dermatology located at 1735 E. Skyline
Drive • Tucson, AZ 85718 • 520-618-1630 • Fax:
520-618-1636
www.ironwooddermatology.org

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