You know that crinkle in your forehead is from your daughter announcing she's quitting the debate team to play drums in a garage band. And that bruise on your thigh is from hauling recycling bins out to the curb. But every so often something pops up on your skin that you can't explain. "Most of the time these things are harmless," says Susan Taylor, M.D., of Society Hill Dermatology in Philadelphia, ticking off a long list of common noncancerous conditions from skin tags to age spots. "But if you're not sure what it is, see your doctor." If it's one of the 3.5 million skin cancers diagnosed in the U.S. each year, the sooner you get treated, the better your chance of being cured. Read on to learn about the changes that can happen to your skin -- and how to protect it.
Step 1: A Skin Cell Goes Rogue
While genetics and ethnicity can be partly to blame for a skin cell turning cancerous, the major culprit is almost always the sun -- real or fake (from a tanning bed). When you're not wearing sunscreen, say while running to the supermarket, ultraviolet rays constantly penetrate your skin. Over many years and many sunburns, these rays can alter the DNA inside your skin cells. They mess with the genes that tell cells when to die off, causing them to grow out of control, explains Ragini Kudchadkar, M.D., a medical oncologist at Moffitt Cancer Center in Tampa, Florida.
People with fair skin -- especially redheads -- are at higher risk for UV damage, as are individuals with more than 50 normal moles or beauty marks, those with a family history of skin cancer or anyone who has previously had skin cancer. And people with darker skin aren't immune from sun damage. In fact, Dr. Taylor points out that their skin cancer is often detected at a later, less curable stage.
Step 2: X Marks a Spot
Your eyes are the best tool for detecting skin cancer. In fact, many women first notice a change while tweezing their brows or shaving their legs -- as well as during monthly checks. Karen Burke, M.D., a New York dermatologist and spokesperson for the Skin Cancer Foundation, says to avoid melanomas, pay particular attention to the ABCDEs: a mole that is asymmetrical, has uneven borders that are scalloped or notched, is a mix of colors rather than just brown, has a diameter larger than a pencil eraser's or has evolved by changing shape, color or size. "And I like to add an F: anything that's funny-looking," she says. (Quick: Quiz yourself right now to see if you remember A through F.)
Dr. Burke points out, though, that as diligent a skin checker as you may be, it's difficult to see some parts of your own body, even with a mirror and some advanced-level yoga poses, so you should also consult your dermatologist for a full-body check. "Every adult should go in for an annual exam by the time she is 18," says Dr. Burke, although she adds that if you missed that deadline, just go ASAP. Depending on your risk level, your doctor might recommend you come back every 3 to 12 months.
Step 3: The Don't-Be-Shy Body Exam
You want your dermatologist to see every inch of your skin, so prepare for an appointment by removing all nail polish, shaving your legs and removing makeup. Your doctor will check you from top to bottom, front to back, in between your toes, on your scalp, even on your breasts and butt. "Some people get embarrassed," says Dr. Taylor. "But I explain that I'm not looking at their body type or whether they need to lose a few pounds. All I notice is skin!" Your M.D. might scan your body with a dermatoscope, which resembles a small magnifying glass and uses polarized light to detect patterns in the skin. Many docs, however, prefer their well-trained eyes. "We may also take some photos of your moles to see if they change over time," Dr. Burke says. A complete exam should only take about 10 minutes.
If your doctor finds a suspicious-looking mole or growth, she'll take a biopsy to determine if it's malignant. After using a needle to inject a small amount of a numbing medicine, she'll remove a sample of the mole by either shaving off a thin layer with a blade or using a small instrument to punch out a tiny core of skin. "If it's on the face, we'll try to take the smallest piece of skin possible so it doesn't leave a scar," says Dr. Burke. Then the sample is sent to a lab for analysis.