Good Fruit Grower / July 2008 / Skin cancers

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Skin cancers

Farmers run a greater risk of skin cancer.

Skin cancer is the most common type of cancer.

One in five Americans develops some type of skin cancer. About one million new cases are reported each year. The risk of developing the most dangerous form, melanoma, is one in 58 for both men and women, but Caucasian men over age 50 are at a higher risk than the general population.

Farmers are at greater risk for developing skin cancers because of their exposure to the sun during outdoor work. The prevalence of skin cancers is three to five times greater in agricultural workers than other industries, and yet farmers are among the least likely to get annual screening for early diagnosis and treatment.

Outdoor workers seem to have less melanoma, the most dangerous kind of skin cancer, but more of the other nonmelanoma types of skin cancers.

Types of skin cancer

There are three broad categories of skin cancers:

• precancerous lesions, which are nonmalignant actinic keratoses

• nonmelanomas, which include basal and squamous cell cancers

• melanomas.

Actinic Keratoses (AKs)

AKs affect about 10 million people annually and are precancerous skin lesions. If left untreated, they can progress to the more serious form of skin cancer, squamous carcinomas. AKs are scaling, peeling, thickened white or yellowish patches of skin between 1/4 and 1 inch in diameter. They are most commonly found in fair-skinned people on the face, lip, back of the hands, forearms, or the top of a balding head. Treatment consists of removal by freezing (cryotherapy) laser, chemical peeling, dermabrasion, or chemotherapy lotions.

Basal Cell Carcinomas

These originate from the lowest or basal layer of the skin and are the most common form of skin cancer, accounting for 80 percent of all cases. They have a variety of appearances. The most classic is a hard, pearly growth that has rolled-up edges with a central indentation that may be pigmented or has blood vessels. It also can be an open sore that does not heal, a flat reddish patch, or a hard white or yellowish area that looks like a scar. These carcinomas are slow growing, reaching up to 1/2 inch, and appear on the head, neck, hands, and, occasionally, the flat types are found on the trunk. They rarely spread to other parts of the body.

Squamous ­Carcinomas

These originate from the upper (squamous) layer of the skin and account for 16 percent of all skin cancers. Like the others, they occur in sun-exposed parts of the body but also can be found in the mouth, on the lips, or on the genitals. These also can appear as a nonhealing growth or ulcer, a wart or plague, or as red scaly bumps and patches. If left untreated, they can metastasize and be fatal. The good news is that if they are caught early and surgically removed, the cure rate is 95 ­percent.

Melanomas

This is the most dangerous kind of skin cancer and one you need to be able to detect early. If left untreated, melanomas spread and can be fatal. An easy way to remember what they look like is to ask the following ABCD questions:

Asymmetry Is it asymmetric? If you were to fold the shape in half, the two sides would not match each other. Melanomas are not symmetrical in shape.

Border irregularity Is the border irregular? If the outer edges of the lesion are notched, blurred, or ragged, it may be a melanoma.

Color Does it have more than one color? Most moles have a uniform color, but melanomas have more than one color, ranging from light to dark to even a reddish hue.

Diameter Is the diameter changing in size? Is it larger than the eraser end of a pencil? Moles stay the same size, unlike melanomas.

Prevention

Avoid the two major ultraviolet (UV) wavelengths that get through our ozone layer which deeply penetrate the skin (UVA) and cause sunburn (UVB). Choose a sunscreen with at least an SPF of 15 that consists of avobenzone (which prevents burns) with the addition of oxybenzone, which provides more ­stability and blocks deeper UVA penetration. Apply daily in amounts ­equivalent to a shot glass.

The American Academy of Dermatology recommends the following practices, in addition to regularly applying ­sunscreen:

1. Wear long-sleeved shirts, pants, a wide-brimmed hat, and dark glasses, the latter to help prevent macular degeneration.

2. Seek shade if possible during hours of maximum sun strength (10 a.m. to 4 p.m.)

3. Avoid deliberate tanning.

4. Get your vitamin D from your diet.

5. Use caution around water, sun and sand, which reflect the sun's dangerous UV waves.

6. Protect children with sunscreen.

7. Every birthday, in your birthday suit, check for ­suspicious lesions. •


Helen Murphy is the director of outreach and education for PNASH (Pacific Northwest Agricultural Safety and Health) at the University of Washington, Seattle.