Although progress is being made on new treatments for skin cancer, preventing skin cancer — or discovering it early if it does occur — are still the best approaches to staying safe from the disease, said an American Cancer Society (ACS) expert.

"The vast bulk of skin cancers in the US are due to excessive skin exposure to UV (ultraviolet) radiation from the sun, so sun protection is the key to preventing the disease," said Martin Weinstock, MD, PhD, director of dermatoepidemiology at Brown University and chair of the American Cancer Society (ACS) skin cancer advisory group.

Melanoma, the type of skin cancer most likely to be life-threatening, is now 15 to 20 times more common than 50 years ago. This is mostly because in recent decades more people have been out in the sun with less clothing than before, Weinstock said.

Lately, more people are becoming aware of the need for sun protection, but melanoma is still on the rise because skin cancers typically take decades after sun exposure to develop, he said.

Sun exposure is also the main reason for the occurrence of non-melanoma skin cancer such as basal cell carcinoma and squamous cell carcinoma.

Weinstock said a few common-sense practices will greatly reduce the chance a person will develop skin cancer:

• Avoid direct sunlight between 10 a.m. and 4 p.m. when ultraviolet (UV) rays are most intense.
• Wear a hat with a brim wide enough to shade your face, ears, and neck, and clothes that cover as much as possible of the arms, legs, and torso.
• Use a sunscreen with a sun protection factor (SPF) of at least 15.
• Avoid tanning beds and sunlamps because they also are sources of UV radiation.

Skin cancers found before they have spread have the highest chances of successful treatment. Weinstock said primary care physicians should do a thorough, full-body skin cancer exam as part of a patient's regular physical exam. He said patients should ask for it if it's not offered.

People should do monthly skin self-exams also, said Weinstock. They should report to their doctor moles that have any of the warning signs of melanoma outlined in the ABCD rule:

• Asymmetry: One half of the mole does not match the other half.

• Border Irregularity: The edges of the mole are ragged or notched.
• Color: The color over the mole is not the same. There may be differing shades of tan, brown, or black, and sometimes patches of red, blue, or white.
• Diameter: The mole is wider than 6 millimeters (mm)—about one-fourth inch—across, although in recent years doctors are finding more melanomas between 3 mm and 6 mm.

Other important warning signs of melanoma include changes in size, shape, or color of a mole. But some melanomas, and other kinds of skin cancer, do not fit the ABCD rule described above. It is particularly important to be aware of changes in skin growths or abnormalities and bring them to the attention of your doctor.

Non-melanoma skin cancers can look like a variety of marks on the skin. The key warning signs are a new growth, a spot or bump that's getting larger, or a sore that doesn't heal within three months.

New techniques of skin cancer treatment and detection are being explored continually, but prevention remains a crucial key to safety from the disease, Weinstock stressed.

"Slip on some protective clothing, slap on a wide-brimmed hat, and slop on the sunscreen for skin that's still exposed, and you'll be doing the most important things you can to protect yourself against a potentially life-threatening skin cancer," concluded Weinstock. In addition to these prevention measures, the ACS also asks people to, "Wrap on sunglasses...and look for shade in the middle of the day."