6 Things Your Dermatologist Wants You to Know About Skin Cancer

Preventing skin cancer isn't always as simple as just wearing sunscreen every day. Your skin tone, family history, and habits from years past can all affect your skin cancer risk. Here, dermatologists explain what you need to know for every skin scenario under the sun.

"Melanoma doesn't discriminate by skin color," says Shelby Moneer, director of education at the Melanoma Research Foundation. In black skin, melanin provides a sun-protection factor of about 13.4 (compared with 3.4 in white skin)—still less than the SPF 15 required for adequate sun protection. Though people of color have a lower overall incidence of skin cancer, their five-year survival rate is only 75 percent, versus 93 percent for Caucasians. "Many people, including some doctors, think that if a person doesn't have fair skin, skin cancer won't happen to them," says Brooke Jackson, MD, associate professor of dermatology at the University of North Carolina at Chapel Hill. "Because of this misperception, if a malignancy is found, it's often at a later, more serious stage."

"If you have a first-degree relative—a parent, sibling or child—who has had melanoma, your chances of getting it are 50 percent higher," says Jennifer Linder, MD, a dermatologist in Scottsdale, Ariz., and spokesperson for the Skin Cancer Foundation. Though experts recommend that the general population get a yearly skin cancer exam with a dermatologist, adults with a family history of skin cancer should be checked every six months.

More than 419,000 cases of skin cancer in the U.S. each year are linked to indoor tanning. If you have used tanning beds in the past (you're not doing it anymore, right?), experts advise that you tell your dermatologist to include that information in your skin cancer history.

The more you have, the greater your risk of skin cancer. About half of all melanomas develop in pre-existing moles. "There are two types of moles: little sun spots, evenly colored and nicely shaped, and what we call atypical moles," Dr. Linder says. Folks who have 10 or more atypical moles, also known as dysplastic nevi (see What Are You Looking For?, page 127), have 12 times the risk of getting melanoma as the general population.

People with light skin, light eyes and light hair have less of the protective pigment melanin in their skin and are more susceptible to sunburns—and more apt to have moles. A recent study of 477 fair-skinned children under age 10 found that those with a gene variant for blue eyes were more likely to develop moles—and those with a gene variant for both blue eyes and red hair were more likely to develop larger moles after sunburns.

"Your risk of melanoma doubles if you've had just one blistering sunburn," Moneer says. But here's the key: It's never too late to start incorporating sun-safe practices, like wearing sunscreen regularly. "It's the cumulative amount of sun over your life that causes skin cancer," she explains. Contrary to popular belief, only about 23 percent of lifetime sun exposure is acquired by age 18. "Changing habits does make a difference," Dr. Linder says.