Mole Screening Why you need it: To detect skin cancer as early as possible. Melanoma, the deadliest form, is the second most common cancer (after breast) among women in their 30s, according to the American Cancer Society. Basal-cell and squamous-cell carcinomas occur more frequently but are nearly 100 percent curable if caught early. When and how often: By age 30 (earlier if you've had extensive sun exposure), you should begin to have an annual skin check. Repeat twice a year after that if you're at high risk - that is, if you've already had a basal-cell or squamous-cell carcinoma, you have a family history of skin cancer, you have many moles, or you have fair skin, red or blond hair, or freckles. What to expect: A dermatologist will examine your body, head to toe - including your scalp, your ears, and the skin between your toes - checking freckles, moles, and skin growths. She may measure any large or unusual moles or even perform digital-imaging screening, a computer scan that provides a close-up view of your moles for future comparison. What the results mean: Your doctor will take tissue samples from any suspicious-looking moles and send them to a lab to be examined. Depending on the results, surrounding tissue may be removed for further evaluation and treatment.