Myths and Facts: Skin Cancer

More than one million people in the U.S. are diagnosed each year with cancer. And, while the overall rate of cancer diagnoses has been declining since 1999, this is not true for skin cancer. Instead, skin cancer diagnoses continue to rise each year.¹

Skin cancer is the 10th most common type of cancer in the U.S. It is divided into two classes: non-melanoma (basal cell and squamous cell carcinomas) and melanoma. Nonmelanoma skin cancers are more common, with about 80 percent of all diagnosed skin cancer cases basal cell carcinomas and approximately 16 percent squamous cell carcinomas. Melanoma accounts for only 4 percent of diagnosed cases, but it is the deadliest form of skin cancer.² Between 1975 and 2006, 1 the number of melanoma cases increased, and in 2010 alone, there was predicted to be an estimated number of 68,130 new cases.³

Why do the rates of skin cancer continue to rise? Likely because of how widely misunderstood it is. But, separating fact from fiction can go a long way toward helping people prevent this oftentimes deadly disease.

Separating Myth from Fact

Myth: Skin cancer is not as serious as other forms of cancer, and is rarely fatal.

Fact: Skin cancer is very serious. There are approximately 11,790 deaths due to skin cancer each year, 8,700 of which are due to melanoma. The overall five-year survival rate for melanoma is 91 percent. As with all other cancers, the earlier the cancer is detected, the more likely one will survive it. For localized melanoma, the five-year survival rate is 98 percent; survival rates for regional and distant stage diseases are 62 percent and 15 percent, respectively. Fortunately, about 84 percent of melanomas are diagnosed at a localized stage.³

Myth: Skin cancer is easy to detect.

Fact: It’s easy to miss or mistake skin cancer. Melanoma can occur anywhere, including the legs, arms, back, neck, palms of the hands and soles of the feet, so it’s important to regularly perform a skin exam.

Even when an exam is performed, it’s common for melanoma to be mistaken for moles. But, melanoma has some distinguishing characteristics that can be identified using the ABCD rules: A for asymmetry, B for border, C for color and D for diameter. While common moles are symmetrical and round, melanomas are asymmetrical, so that if a line is drawn through the middle, the halves would not be symmetrical. Melanomas also are often uneven and have notched edges, whereas moles have even, smooth borders. Moles appear as a single shade of brown, whereas melanomas vary in shades of brown, black and tan, and as they progress, the colors red, blue and white may appear. And, melanomas tend to be larger than moles, which are typically about the size of a pencil eraser.⁴

Myth: People with dark features are not at risk of developing skin cancer.

Fact: People with lighter hair, light-colored eyes and fair skin, as well as those who have numerous moles, are six times more likely to develop melanoma than people with darker features.⁵ But, all people are at risk. People with dark skin have additional protection because they have more melanin, which filters UV radiation, but when diagnosed with melanoma, it’s typically at an advanced stage.⁵

There also is the mistaken belief that people with a tan are less likely to develop cancer. Tanned skin is just damaged skin, and repeated tanning injures the skin and increases the risk of skin cancer.⁶

Myth: Skin cancer is caused only by prolonged exposure to the sun.

Fact: It is true that excessive sun exposure increases the risk of skin cancer. But, even minimal exposure to the sun causes skin cancer. On a cloudy day, 85 percent of ultraviolet (UV) rays can still penetrate, leaving people equally at risk in the car, walking the dog or letting their children out to play at any time of the year. 6 Even so, the American Academy of Dermatology advises individuals to avoid the sun when its rays are the strongest, between 10 a.m. and 4 p.m.⁷

In a recent study, scientists found that an immune protein actually exacerbates cancer due to sun exposure. Because of the rising rates of melanoma, researchers at George Washington University Medical Center in Washington, D.C., have been examining the link between UV rays and melanoma for more than a decade. In their study, they found that UVB rays cause white blood cells, called macrophages, to migrate higher in the skin of mice and release an immune protein, interferon-y. But, instead of protecting the body like most interferon proteins do, interferon-y allows tumors to grow by preventing the body’s natural immune response.⁸

Myth: People need some exposure to the sun to ensure they get enough vitamin D.

Fact: Actually, normal vitamin D levels are primarily maintained through a normal diet, rather than through exposure to sunlight. According to the National Institutes of Health, “Despite the importance of the sun for vitamin D synthesis, it is prudent to limit exposure of skin to sunlight.”⁹

Many dermatologists agree. “As a dermatologist who treats the ravages of skin cancer on a daily basis, it is appalling to me that anyone in good conscience could make the claim that intentional sun exposure — for any length of time — is beneficial,” says Darrell S. Rigel, MD, clinical professor at the NewYork University Medical Center in New York. “Until there is science that tells us otherwise, it is imperative that people protect themselves from the sun. Anyone concerned about not getting enough vitamin D should either take a multivitamin or drink a few glasses of vitamin D-fortified milk every day. Given the fact that the U.S. Department of Health and Human Services has declared UV radiation as a known carcinogen, exposing oneself to it for the sake of vitamin D is not the answer.”⁷

Myth: Using sunscreen, especially those with high SPF ratings, will prevent skin cancer.

Fact: Sunscreen is not a panacea for preventing skin cancer, but it should be used to reduce risk. And, sunscreen is recommended only as one component of a multipronged sun safety strategy, which also includes wearing protective clothing, limiting sun exposure and avoiding the sun during peak hours. Unfortunately, according to a 2009 survey of 1,000 adults, almost one-third of all Americans don’t use sunscreen at all, and 69 percent report using it only occasionally. What’s worse are the misconceptions about sunscreen that reduce its effectiveness, even when it is used.¹⁰

SPF, which stands for sun protection factor, is a number that indicates how long it will take for UVB rays to redden skin when using a sunscreen product, compared to how long the skin would take to redden without the product. The higher the SPF, the longer skin can be sun-exposed before burning. 11 But many people believe that once sunscreen is applied, they are protected. Sunscreen should be applied at least every two hours, especially when swimming or sweating, even if the sunscreen is labeled “water-resistant.” In addition, it should be applied 15 to 30 minutes prior to going outdoors to allow it time to absorb into the skin. And, after a year, sunscreen loses some of its effectiveness, and it is completely ineffective after three years.¹⁰

There also is a problem with how sunscreen is labeled and rated. In the U.S., a sunscreen’s effectiveness is only measured by SPF, which indicates how much protection it provides against UVB rays. UVB rays, which are short-wave radiation with wavelengths of 290 to 320 nanometers, were long considered the main wavelengths behind skin cancer. However, more recent research shows that UVA rays, long-wave radiation of 320 to 400 nanometers, are the predominant cause of premature skin aging and also a significant cause of skin cancer. While UVA rays don’t burn the skin, they invade the skin more deeply than UVB rays, possibly producing even more damage.

Many sunscreens in the U.S. provide UVA defense, but the U.S. has no criteria for determining or labeling a sunscreen’s level of UVA protection (whereas outside of the U.S., particularly in Europe, there is such criteria). So, the Food and Drug Administration (FDA) is considering several labeling changes: 1) a one- to four-star rating system would be used to gauge UVA protection, with one star the lowest and four the highest. Products without a star would be marked “No UVA protection.” 2) Sunscreen packaging must include a warning that sunscreen is just one part of a comprehensive sun protection program, along with instructions to reapply every two hours, limit sun exposure and wear protective clothing. 3) Whereas now SPF numbers are as high as 100, they would be limited to 50+. An SPF of 15 filters out 93 percent of UVB, SPF 30 filters out 97 percent and SPF 50 filters out 98 percent. Numbers over 50 offer negligible increases in protection. 4) The term “sun protection factor” would be changed to “sunburn protection factor.” 5) The terms “waterproof” and “sunblock” would be disallowed, as no product is impervious to water or able to fully block the sun’s rays. Sunscreen that retains its SPF after 40 or 80 minutes of immersion in water would be labeled “water resistant” or “very water resistant,” respectively. The FDA had announced that it would rule on these proposals by October 2010, but as of this writing, no ruling has been made.¹¹

One last misconception about sunscreen pertains to selftanners. Self-tanners only stain the skin’s top layer a bronze hue. In fact, a German study showed that self-tanners increase sun damage, especially after exposure to sun an hour or so after applying tanner. This is because the skin may produce 180 percent more free radicals (unstable molecules that damage cells, potentially leading to skin cancer) than it would have had the product not been used.¹

Myth: Indoor tanning beds don’t cause skin cancer.

Fact: Twenty minutes of exposure in a tanning bed is roughly equivalent to four hours in the sun.⁵ Unfortunately, while teen indoor tanning has decreased since 2005, recent usage by girls remains high, with more than 10 percent of all girls ages 14 to 17 and 16 percent of non-Hispanic white girls of the same age using an indoor tanning device in 2008.¹

Myth: People who have had prior prolonged sun exposure or sunburns don’t need to worry about getting skin cancer if they take care of themselves later.

Fact: It can take up to 20 or more years for skin cancer to develop. It was originally reported by the Skin Cancer Foundation that most people receive about 80 percent of their lifetime sun exposure before age 18. But, recently, the Skin Cancer Foundation revealed that 47 percent occurs between ages 19 and 40. By protecting against sun exposure now, it’s possible to lessen the effects of past exposure. A study in the New England Journal of Medicine showed that people who used sunscreen daily saw a reduction in the number of new precancerous sun spots and a slowing development of preexisting ones.¹²

Dispelling the Myths Now

The days of lathering with oil and lying in the sun for hours upon hours are history. But, that hasn’t stopped the incidence of skin cancer from rising. Individuals need to be factually informed about what they can do to prevent this deadly disease before it is too late for them or a loved one.