According to the Centers for Disease Control and Prevention (CDC) and the American Academy of Dermatology (AAD), one million new cases of skin cancer are diagnosed each year. That gives skin cancer the unfavorable distinction of being the most common form of cancer in the United States. As reported by Dr. Darrell S. Rigel of the New York University School of Medicine, the chance for an American to develop melanoma in their lifetime is 1 in 84. Those aren’t the kinds of odds you want to gamble on, at least not when it comes to losing portions of your skin or your life.

Most skin cancers fall into three categories: basal cell carcinomas, squamous cell carcinomas, and melanomas. Basal cell carcinomas and squamous cell carcinomas are caused by repeated, unprotected sun exposure (Sources: Cancer Epidemiological Biomarkers and Prevention, September 2008, pages 2388–2392; Dermatology, February 2008, pages 124–136; American Journal of Clinical Dermatology, May-June 2000, pages 167–179).

However, there is some controversy as to whether melanomas are caused by unprotected sun exposure. Despite the disagreement, what is not in question is that other types of skin cancers are caused by unprotected or prolonged sun exposure. (Sources: Archives of Dermatology, December 2000, pages 1447–1449; and Journal of the American Medical Association, June 2000,pages2955–2960.)

As a general theory, scientists believe that exposure to UVA and some UVB radiation triggers mutations in replicating skin cells, causing their genetic coding to go haywire. The cells forget how to maintain the normal cell turnover process because of the radiation damage. Fortunately, nonmelanoma skin cancers are relatively easy to treat if detected in time, and are rarely fatal. Melanomas are a much more dangerous and life-threatening form of cancer.

An article in the Journal of Epidemiology (December 1999, Supplement, pages 7–13)  summed up the issue quite nicely: “Skin cancer is the most commonly occurring cancer in humans…. Descriptive studies show that incidence rates of the main types of skin cancer, basal cell carcinoma, squamous cell carcinoma and melanoma are [highest] in populations in which ambient sun exposure is high and skin transmission of solar radiation is high, suggesting strong associations with sun exposure. Analytic epidemiological studies confirm that exposure to the UV component of sunlight is the major environmental determinant of skin cancers and associated skin conditions and evidence of a causal association between cumulative sun exposure and SCC, solar keratoses and photodamage is relatively straightforward…. Complementary to [population and research] data is the molecular evidence of ultraviolet (UV) mechanisms of carcinogenesis [cancer] such as UV-specific mutations in the DNA of tumor suppressor genes in skin tumors. With increased UV irradiation resulting from thinning of the ozone layer, skin cancer incidence rates have been predicted to increase in the future—unless, as is hoped, human behavior to reduce sun exposure can offset these predicted rises.”

Other than sun protection, you should be aware of some early, telltale signs of skin cancer. Early detection of skin cancer can save your skin and your life. If you perceive a change in your skin that you are not sure about, talk to your doctor; even a minor difference in a mole or a freckle, or a blemish that doesn’t look “normal,” can be an indication of skin cancer.

The five most typical characteristics of skin cancer are:

1. An open sore of any size that bleeds, oozes, or crusts and remains open for three or more weeks. A persistent, nonhealing sore is one of the most common signs of early skin cancer.
2. A reddish patch or irritated area that doesn’t go away and doesn’t respond to cortisone creams or moisturizers. Sometimes these patches crust over or flake off, but they never go away completely.
3. A smooth growth with a distinct rolled border and an indented center. It can look like a small blemish or wound, but tends to grow and doesn’t heal.
4. A shiny bump or nodule with a slick, smooth surface that can be pink, red, white, black, brown, or purple in color. It can look like a mole, but the texture and shine are what make it different.
5. A white patch of skin that has a smooth, scarlike texture. The area of white skin can have a taut, clear appearance that stands out from the appearance of the surrounding skin.

The American Academy of Dermatology has a list of the “A, B, C, Ds” of identifying skin cancer, as follows:

• A. Asymmetry: One half of the lesion or suspect area is unlike the other half.
• B. Border: There is an irregular, scalloped, or poorly circumscribed border around a suspected skin lesion or mole.
• C. Color: Color varies from one area to another, with shades of tan, brown, black, white, red, or blue.
• D. Diameter: The area is generally larger than 6mm (diameter of a pencil eraser). 

Actinic Keratosis

If you have had any amount of unprotected sun exposure and you are between the ages of 30 and 80 you might have noticed uneven, rough-feeling, slightly raised, occasionally crusty, and generally light brown or light pink patches on your chest, hands, arms, or neck. These discolorations are called actinic keratosis or solar keratosis, and are distinct from other types of brown discolorations that show up on skin. According to the Skin Cancer Foundation, “One in six people will develop an actinic keratosis in the course of a lifetime.” The more typical brown spots that appear on skin due to sun exposure are called melasmas. Melasmas look more like brown freckling and are not raised, rough, or crusted, and are considered benign. Actinic keratosis, though not cancerous, are problematic because they are considered indicative of a precancerous skin condition and require evaluation by a dermatologist. If you are in doubt whether a brown patch on your skin is a melasma or an actinic keratosis, it is best to ask your doctor. (Source: Journal of Oral Maxillofactory Surgery, June 2008, pages 1162–1176.)

Prevention is the best method of averting the occurrence of these types of brown patches, and that means daily and liberal use of effective sunscreens. Unfortunately, because most of us were not aware of appropriate sun protection for much of our lives, many of us have a pretty good chance of seeing one of these patches crop up somewhere on our bodies.

There are a number of ways to deal with removing actinic keratosis. The primary techniques are curettage, cryosurgery, and photodynamic therapy, plus topical chemotherapy options (Sources: Dermatology Therapy, September-October 2008, pages 412–415; and American Journal of Clinical Dermatology, May-June 2000, pages 167–179).

Removing Actinic Keratosis

Deciding what to do depends primarily on the status of the lesion and how much the appearance bothers you. This requires a discussion with your dermatologist to evaluate your various options.

A typical method of removal is to scrape or cut the lesion off with procedures called curettage, electrodesiccation, or even simple scraping with a surgical razor. Curettage refers to cutting out the lesion with a curette, a spoon-shaped implement that has a sharp edge. Electrodesiccation uses an electric current to remove the skin tissue while it simultaneously controls bleeding. In both instances a biopsy is done to check on the status of the lesion. Both of these methods can cause scarring, and recurrence of the lesions is a problem.
Cryosurgery uses extreme cold, in the form of liquid nitrogen, to get rid of the unwanted tissue. This method doesn’t cause bleeding or scarring but it can leave behind a white mark that often doesn’t regain normal skin color. There is also a strong likelihood of recurrence.

When there are numerous actinic keratosis lesions present, two topical medications are sometimes used. The first, 5-fluorouracil (brand name Efudex), a chemotherapy agent for some cancers, is applied to the spots twice a day for three to five weeks. The side effects of this treatment can be significant, though temporary. Inflammation, burning, stinging, crusting, and some discomfort or pain are typical, but healing takes place one to two weeks after treatment is discontinued. It is considered a highly effective treatment.

Another chemotherapy agent used topically, masoprocol cream, 10% (brand name Actinex), is similar to 5-fluorouracil in terms of application and results, although there is a far higher risk of contact dermatitis with masoprocol than with 5-fluorouracil.

Immune response modulators are capable of selectively destroying abnormal skin cells. In a small study group “six men with actinic keratosis were treated with imiquimod 5% cream (trade name Aldara) three times a week for 6-8 weeks. In the event of a local skin reaction treatment was modified to two times per week. Results: All the AK [actinic keratosis] lesions were successfully cleared…. Histologically [under the skin], no apparent signs of persisting AK could be detected, and no recurrences were reported during follow up” (Source: British Journal of Dermatology, May 2001, pages 1050–1053). Aldara is a potential option to discuss with your physician.

Chemical peeling uses trichloroacetic acid (TCA), which is applied under light sedation. Much like any other cosmetic chemical peel, this causes the top layers of the skin to slough off, to be replaced within a few weeks by growth of new skin. A TCA peel is used when deeper penetration is needed to remove the lesion. The downsides to this method are the need for sedation, which makes it rather inconvenient, and the prolonged healing time; the upside is that the eventual results are considered quite good.

The newest treatment recently approved by the FDA is called photodynamic therapy. This is an interesting procedure that involves the topical application by a physician of a prescription-only cream containing aminolevulinic acid (brand name Levulan Kerastick). About 14 to 18 hours after the cream has been applied, the area is exposed to a particular light source, called BLU-U or Blue Light, for approximately 15 to 20 minutes. This is considered a very successful treatment with little risk to skin. However, after the aminolevulinic acid has been applied, the skin becomes abnormally sensitive to daylight or bright indoor lighting until the treatment is completed. It is critical to wear sunlight-protective clothing and to avoid any exposure to the sun because sunscreens will not protect you. It is also important to avoid sitting close to any light source. Side effects during treatment usually include burning, a crawling feeling on skin, itching, numbness, and stinging sensations, darkening or lightening of treated skin, crusting, scabs, and red itchy bumps. However, once treatment is discontinued the reaction and brown spots are gone and tend not to return.