Identifying signs of skin cancer, plus prevention tips

Kristin Cam Missmar, MD, FAAD, a board-certified dermatologist with the Mid-Atlantic Permanente Medical Group, tells us what to look for during a self-examination of our skin.

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By Kristin Cam Missmar, MD, FAAD

Most people already know that the sun’s ultraviolet rays are a primary cause of skin cancer, yet it remains the most commonly diagnosed cancer in the United States, with one in five people developing some form of the disease in his or her lifetime, according to the American Cancer Society. The vast majority of these cases, including the ones I see in my office, are basal cell and squamous cell carcinomas, skin cancers that can typically be removed in an office visit and are much less likely than melanoma to spread to other parts of the body—although if they are left untreated and continue to grow, they sometimes do.

While the majority of skin cancers are treatable, the best way to modify your risk and avoid more serious disease is through prevention and early detection. Keep in mind that although summer might be prime time to think about sun exposure and protection, protecting your skin is really a year-round job. Below, I share some of the advice I give patients to help them decrease their risk of developing skin cancer.

Preventing Skin Cancer

When it comes to decreasing skin cancer risk, prevention is key, and it is largely a matter of limiting sun exposure. The same rules apply for both adults and kids, and I frequently remind parents to be as good about sun protection for themselves as they are for their children.

Using sunscreen is crucial, so look for sunscreens that are water-resistant, broad spectrum (meaning they protect from both ultraviolet A and ultraviolet B rays) and have an SPF of at least 30. If you have sensitive skin, it can help to use sunscreens that contain only zinc oxide and titanium dioxide, ingredients that tend to be less irritating to the skin. Also, be sure to adhere to your sunscreen’s expiration date.

Sunscreen is not effective unless applied correctly, so use enough—for adults, one ounce, enough to fill your palm—and apply often. It is best to apply 15 minutes before going outdoors, and then re-apply every two hours and after swimming or excessive sweating. Don’t forget to cover frequently missed areas such as your ears and the tops of your feet. For your lips, use lip balm with sunscreen in it.

I like to encourage my patients to consider investing in sun protective clothing, too, especially if they spend a lot of time outdoors on a regular basis for work, hobbies or sports. Choose clothing with a UPF (ultraviolet protection factor) label of 30 or higher. Wide-brimmed hats and UV-blocking sunglasses can also help keep the sun off of your face.

Seek shade whenever possible, and if you can, avoid being outdoors between 10 a.m. and 2 p.m., when the sun’s rays are the strongest. It should go without saying that tanning beds should be avoided completely.

Detecting Skin Cancer Early

Unfortunately, even people who do their best to protect against the sun can be at risk for skin cancer. So even if you do all of the above, it is still important to monitor your skin regularly.

What to Look For

Three of the most common types of skin cancer—basal cell carcinoma, squamous cell carcinoma and melanoma—vary in appearance, but in general, be sure to look out for any lesions that are new, growing or changing. Lesions that change in size, color, shape or texture, or lesions that do not heal, all raise skin cancer suspicions. Any growth that is an “ugly duckling,” or not similar to any other lesion you have, is another red flag. Should any concerning lesions develop, be sure to have them evaluated by a physician as soon as possible.

Know Your ABCDEs

Melanoma is the deadliest of skin cancers, but it is treatable if caught in its early stages. Melanoma may appear as an unusual or changing mole. Below are the ABCDE warning signs of melanoma that you should look for during monthly self-examinations of your skin. Examine yourself head to toe and front to back, using a full-length mirror. You can use a handheld mirror to examine the back of your body and other areas that are hard to see.

  • Asymmetry: Benign lesions are often symmetrical. If you have a mole that isn’t, that could signal melanoma.
  • Border: The edges of benign moles are typically smooth and even. The borders of melanoma may be scalloped or notched.
  • Color: Benign lesions are usually one color. Melanoma often has a variety of shades of brown—and sometimes red, white, and even blue—within it.
  • Diameter: Benign moles are often small, whereas larger moles that are 6 mm or the width of a pencil eraser can be a red flag.
  • Evolving: Moles or other lesions that are benign do not tend to change rapidly. Significant change in any way—color, texture, size, shape—may be a warning sign.

If you see any of these indicators, make an appointment with your physician or dermatologist without delay. Monitoring your skin regularly will help you become familiar with the lesions present on your body and will hopefully allow you to detect any warning signs quickly.

For more information and to see photos of examples of different types of skin cancer, visit the American Academy of Dermatology and the Skin Cancer Foundation websites.


Kristin Cam Missmar, MD, FAAD, is a board-certified dermatologist with the Mid-Atlantic Permanente Medical Group. She sees patients at the Kaiser Permanente Falls Church Medical Center.

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