Prevention

Most skin cancers are preventable. To protect yourself:

Avoid the sun between 10 a.m. and 4 p.m. Because the sun’s rays are strongest during this period, try to schedule outdoor activities for other times of the day, even in winter or when the sky is cloudy. You absorb UV radiation year-round, and clouds offer little protection from damaging rays. Remember, sunburns and suntans cause skin damage that can increase your risk of developing skin cancer. Sun exposure accumulated over time also may cause skin cancer.
Wear sunscreen year-round. Sunscreens don’t filter out all harmful UV radiation, especially the radiation that can lead to melanoma. But they play a major role in an overall sun protection program. Be sure to use a broad-spectrum sunscreen, which means the product blocks both UVA and UVB rays. Select sunscreen products with a sun protection factor (SPF) of at least 15. Use a generous amount of sunscreen on all exposed skin, including your lips, the tips of your ears, and the backs of your hands and neck.For the most protection, apply sunscreen 20 to 30 minutes before sun exposure and reapply it every two hours throughout the day, as well as after swimming or exercising. Apply sunscreen to young children before they go outdoors, and teach older children and teens how to use sunscreen to protect themselves. Keep sunscreen in your car as well as with your gardening tools and sports and camping gear.
Wear protective clothing. Sunscreens don’t provide complete protection from UV rays. That’s why it’s a good idea to also wear dark, tightly woven clothing that covers your arms and legs, and a broad-brimmed hat, which provides more protection than a baseball cap or visor does. Some companies also sell photoprotective clothing. A dermatologist can recommend an appropriate brand. Don’t forget sunglasses. Look for those that block both UVA and UVB rays.
Avoid tanning beds and tan-accelerating agents. Tanning beds emit UVA rays, which may be as dangerous as UVB rays — especially since UVA light penetrates deeper into your skin and causes precancerous skin lesions.
Be aware of sun-sensitizing medications. Some common prescription and over-the-counter drugs — including antibiotics; certain cholesterol, high blood pressure and diabetes medications; birth control pills; nonsteroidal anti-inflammatories such as ibuprofen (Advil, Motrin, others); and the acne medicine isotretinoin (Accutane) — can make your skin more sensitive to sunlight. Ask your doctor or pharmacist about the side effects of any medications you take. If they increase your sensitivity to sunlight, be sure to take extra precautions.
Check your skin regularly and report changes to your doctor. Examine your skin often for new skin growths or changes in existing moles, freckles, bumps and birthmarks. With the help of mirrors, check your face, neck, ears and scalp. Examine your chest and trunk, and the tops and undersides of your arms and hands. Examine both the front and back of your legs, and your feet, including the soles and the spaces between your toes. Also check your genital area, and between your buttocks.
Have regular skin exams. Consult your doctor for a complete skin exam every year if you’re older than 40, or more often if you’re at high risk of developing skin cancer.

To detect melanomas or other skin cancers, use the A-B-C-D skin self-examination guide, adapted from the American Academy of Dermatology:

A is for asymmetrical shape. Look for moles with irregular shapes, such as two very different-looking halves.
B is for irregular border. Look for moles with irregular, notched or scalloped borders — the characteristics of melanomas.
C is for changes in color. Look for growths that have many colors or an uneven distribution of color.
D is for diameter. Look for growths that are larger than about 1/4 inch (6 millimeters).