My 20 Years of Skin Cancer

Spot a Precancer

Actinic keratoses More than 10 million Americans have these scaly or crusty growths; one in 10 may become a squamous-cell cancer.

Dysplastic nevi, or atypical moles They're benign, but having them increases your risk of melanoma. Because their irregular borders and multiple colors mimic the deadly skin cancer, you should have them checked by a dermatologist.

Seborrheic keratoses These skin growths have a warty surface or waxy appearance. A dermatologist can confirm if they're benign.

Treatment Your dermatologist can shave, freeze, or cut off a growth that's precancerous. He can also prescribe a chemo cream such as Zyclara, which was approved by the FDA in March for treating actinic keratoses (side effects include redness, scabbing or crusting, and sores or ulcers). Ask about photodynamic therapy, which involves treating the skin with a chemical that lets a certain wavelength of light destroy the precancerous cells without harming healthy ones.