(Be aware that this post is longer than what you’ll usually see here. There’s just lots to say about the topic.)
I’m just back from a vacation in the Caribbean. (That’s why I’ve been away from this blog.) There’s a tree native to the region called the papelillo. It’s also called the “gringo tree,” because the bark turns red and peels off—just like the skin of gringos who come down and get too much sun too fast. And sure enough, I saw plenty of people who had overdone their sunning and were suffering the effects.
Lots of other people had gone overboard the other way, too—after days in the sun they were just as pasty as when they stepped off the plane. While obviously those who had been burned hadn’t done things right, those who didn’t get any color were wrong, too. I’ll talk about why you need sun in another post. In the meantime, here’s why you do need to be sensible about sun exposure.
The big fear of sun exposure is the development of skin cancer. There’s no question that ultraviolet radiation from the sun can cause changes in skin cells. The most common is a non-cancerous form known as actinic keratosis. This is an area of brown or reddish skin that may feel rough. Over time it can turn into the most common form of skin cancer, squamous cell carcinoma. The next most common form is basal cell carcinoma. These two forms make up more than 90 percent of cases of skin cancer. The third kind is melanoma, considered much more serious. The two types of carcinoma, if left untreated, can eventually grow large enough to be disfiguring—and in rare cases can actually be fatal. The real worry is melanoma, though, because this form has a much greater chance of spreading throughout the body and eventually doing you in.
What’s the Real Story on Sun and Skin Cancer?
More than 30 years ago the Australian health authorities developed a public awareness campaign they called “Slip, Slop, Slap”—Slip on a shirt, Slop on sunscreen, and Slap on a hat. At the time the rate of skin cancer there was alarmingly high—nearly three times that in the US—and climbing. Some studies claimed to show a link between the amount of sun exposure and the risk of developing skin cancer, so it seemed to make sense to reduce exposure to the sun.
In spite of this effort, the net effect on skin cancer in Australia has been minimal. While the rate of the carcinomas has dropped significantly, the incidence of the dangerous melanoma has actually risen by about 60 percent since the beginning of the campaign. Supporters of the campaign point to the first fact as proof of success. But they ignore the second fact, that the number of deaths from skin cancer has been rising steadily.
And the story isn’t any better in this country. The rate of skin carcinomas has been falling, while melanoma is the only one among the more common types of cancer whose rate has been rising—nearly tripling between 1972 and 2006.
With the increased attention to sun exposure, and so much use of sunscreen with higher and higher SPF levels, something’s clearly out of whack. Either sunscreen itself is a problem (I’m not going there, at least not today) or the entire premise of “more sun = increased risk” is wrong.
We’re built to deal with sun exposure just fine. People who spend much of their lives outdoors (farmers, construction workers, etc.) have very low rates of skin cancer compared to the general population. And, curiously, when the more dangerous melanoma form of skin cancer does develop in these people, it tends to appear in areas not exposed to the sun, such as the buttocks and the inner side of the upper arms. So be sensible about your sun exposure—an increased number of bad sunburns in your life increases your risk of developing some form of skin cancer—but don’t worry too much about regular time in the sun.
What to Watch For
You probably already know this, but it’s helpful to include the signs to watch for. The useful mnemonic is ABCDE.
- Asymmetry—Moles are almost always round or nearly so. If you have a spot that’s irregularly shaped, or that has changed shape, get it checked out.
- Border—Moles typically have a clearly defined border.
- Color—Moles are almost always brown or black. If you have something that’s a different color, or more than one color, or that has changed color, that’s a bad sign.
- Diameter—Moles are most often less than ½ inch (that’s about 1 cm) in diameter. If it’s larger than that, or if it’s been growing, it needs to be looked into.
- Elevation—Moles are flush with the surface of skin. Anything that’s elevated, especially if it has a rough texture, is worth further inspection. (Sometimes you’ll see the E as standing for “Evolving,” but that’s pretty much taken care of under the other headings.)