Summer sun means summer fun, but it also carries increased risks for skin cancer.

Summer is here, but all that planned fun in the sun can have a downside: an increased risk of skin cancer.

Of all the cancers possible – and there are dozens – skin cancer is the most common and can be one of the most easily cured, said Dr. Joseph Andrews of Dover’s Delaware Dermatology PA.

Even though a 20-year study in Sweden published in the Journal of Internal Medicine showed exposure to the sun has many benefits -- preventing a Vitamin D deficiency, for example -- dermatologists also know too much of a good thing can have the opposite effect.

Everyone can contract skin cancer, Andrews said, and it’s not just light-skinned people who may develop the disease.

Those with dark skins, including African Americans, Latinos and American Indians, also are vulnerable, although many may not realize this to be the case.

“Anyone, regardless of skin color, can get skin cancer,” Andrews said. “Some of the more advanced melanomas I’ve seen have been in darker-skinned individuals.

“I think it’s because they falsely believe they can’t get skin cancer or because they didn’t get it checked as quickly as they should have.”

Three basic skin cancers

According to the American Academy of Dermatology, most skin cancers are the result of exposure to ultraviolet light, either from the sun or from tanning beds.

Cancers develop when UV radiation penetrates the skin and damages DNA found in each cell.

“Once you put a chink in the DNA of a cell, it makes that cell grow in an abnormal way,” he said. “Instead of doing what they normally do, their primary goal is to grow and reproduce, producing cells like itself, which is a cancer cell.”

There are three basic forms of skin cancer, Andrews said. Many develop from skin moles, which are common in people of all races.

Basal cell carcinoma is the most common skin cancer, with more than two million cases diagnosed each year.

Andrews describes basal cell carcinomas as cells that tend to clump together; they rarely break off and travel to other parts of the body. This makes them relatively easy to remove.

They’re the least troublesome when found on a patch of open skin, he said.

“If I had one on my arm, it would be very easy to treat,” he said. “If I had one by a tear duct, it could grow into the tear duct and cause significant problems.”

Squamous cell carcinomas look like scaly, thick patches akin to warts. About 700,000 cases are diagnosed each year in people whose skin has been exposed to solar radiation for extremely long amounts of time. These cancers also have a tendency to develop on women’s legs, which generally are more exposed to UV radiation than those of men.

The least common but most serious skin cancers are the melanomas, which develop in the cells that produce melanin, the substance that gives skin its color. They’re in the deepest layer of skin

 and those ethnicities with greater amounts of the melanin have less chance of developing the disease.

But darker-skinned people still develop melanoma, Andrews said. These cancer cells tend to break off from a developing tumor and travel through the bloodstream, lodging in other parts of the body.

“They can easily travel to distant sites and may stop in the kidney, liver or brain and start growing there,” he said. “That’s what makes melanoma so deadly.”

Symptoms easy to spot

As cancer cells grow, they crowd out other cells so that the affected organs stop their normal functioning.

Andrews recommends everyone, regardless of race, regularly examine their skin and become aware of what are known as the “ABCDEs” of skin cancer:

A - Asymmetry: moles or lesions generally are circular, with one half looking like the other half. If they are not, be suspicious.

B - Border irregularity: normal moles or lesions have a clearly defined border; cancer cells have irregular edges.

C - Color: cancer cells vary in color, with different shades of brown, tan or black.

D - Diameter: moles greater than six millimeters (about one-quarter inch) in diameter.

E - Evolution: moles that grow or change shape or color.

Any of these symptoms should mean a trip to a dermatologist, Andrews said.

“Moles should not be changing,” he said. “If you see a mole that’s changing, then that’s suspicious. If people have an awareness of that and maintain some type of regiment to check themselves, that can avoid a lot of problems.”

“Moles are normal and most are absolutely benign,” Andrews said. “But any mole can turn into a skin cancer, so any changes should be taken seriously.”