Skin Cancer Myths

M. D. Anderson Cancer Center
Date: May 2008

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Dr. Susan Chon, assistant professor of dermatology at M. D. Anderson Cancer Center, dispels skin cancer myths during a lecture on skin cancer prevention.

And here's some myths we're gonna tackle.

Does sunscreen cause cancer? There was a time when some of these studies came out and they were controversial because people said, "Oh my gosh, it looks like it's causing cancer." And the problem was a lot of the studies were based on recall data. They have the patients fill out basically forms of their behavior twenty-years ago. There's a lot of recall, you know, bias meaning that they didn't really accurately recall how much sun they were exposed to, what they actually did on a regular basis. The previous sunscreens are nothing like the ones we use today. Most of them in fact, they didn't say sunscreen. They said sun lotion, or suntan lotion and had SPF 4 and of 6. So that wasn't really protective. 

People also have this altered sense of immunity when they go out with sunscreen, they're like, oh, I'm invincible. And you know, it's not an impenetrable barrier. It's a temporary -- you know, decreasing your exposure to the sun. It doesn't keep you protected all day long, a hundred percent. 

And then of course one thing about sun is it changes the immunity of your skin. That's why we have these light boxes at the cancer center to treat skin diseases. We know that light therapy helps a little bit of acne, helps psoriasis, and helps atopic dermatitis. It helps, you know, all kinds of lymphomas of the skin because it decreases the immunity of your skin itself. So that also can lead to an increased, you know risk of developing a skin cancer of the skin. So it works both ways, it alters the DNA, it also decreases the local immunity that will protect you from developing skin cancer.

Here's another question. Do sunscreens cause Vitamin D deficiency? No, because, as I mentioned, sunscreens cover just a part of your body. They're not long lasting, they're actually very, you know kind of -- unevenly applied. And if you live in Texas, you're gonna get enough sun from vitamin D, I promise. And they've done huge studies. 

They did a huge study in Australia. They followed people for two years. Australia has the highest rate of melanoma in the world and they're very aggressive about protecting their people. So they had people wear sunscreens, hat and long-sleeved sun protective clothing. They avoided the mid-day sun and they checked their vitamin D levels throughout the year and it was fine all year long. Australia granted -- it's very, very sunny, it's very close to the equator. 

So they tried a different country. They tried Spain as well and again they did similar things and their vitamin D did not fluctuate even seasonally. It's -- for most people it's very hard to be deficient, but I've had some patients we've checked them and they literally are house-bound. They didn't do anything outdoors. And those patients, yes they do need to supplement vitamin D, but there's non-cancer causing ways to supplement vitamin D. You don't go lay out in the sun. You can take a vitamin D pill and it does bring up your vitamin D levels.

Tanning beds, are they safe? No, they're not. Definitely not safe and unfortunately, this generation of teenagers has been -- you'd be surprised when I ask them, have you used them, oh yeah, all the time. Or I do it every time for prom, or you know I do it for whatever special occasion or my spring break. And so this is a different generation, they're very used to being out in tanning beds and that's something that really needs to change and so the American Academy of Dermatology has been very aggressive about legislating and stating that children under 18 cannot go to tanning beds unless they have, you know parental permission because the studies have already shown that there's an increased risk of melanoma with the use of tanning beds. So basically you're having these minors pay to have their sun damage, to increase their risk for developing a very deadly skin cancer, so they're very bad.

What can you do to achieve that look? Use the sunless self-tanners and there's different ways of doing that. There's so many, I mean everyone has, you know their foot in this market, but some that I've heard from patients that Clarins looks very natural, The Jergens Daily Glow looks very natural. And so a lot of the teenagers that I see, and young patients in general, they wanna have not this pale look. They wanna look a little bit tan, use the sunless tanners, they're safe. All they do is stain the superficial layers of your skin, so it does slough off in about a two or three week period. But if you apply it daily, it just kind of stays like a light glow. If there's some very big event, I tell the teenagers to go get sprayed professionally and they look really good, you know, but it's a mindset change, so we have to kind of, you know, get people to try this earlier. 

And one of the things were doing a study on right now is there's this device called the DermaScan. And you put your face in the booth and you can see how much sun damage is on your face. And I've been doing it -- I had two recent skin cancer screenings at the college level, at U of H and at University of Saint Thomas and that's a very hard target audience. You can just imagine they're invincible. So I put -- because they get to go into the box, and they're like, ahh, there's so much screaming. Because you know, you just don't know. You know, you don't know and you can't see it because it's developing very slowly, but under that, kind of a woods lamp or a light, it's a black light, it shows you all you're freckling, all the red spots that are starting to emerge and it's been a really effective tool. We're studying it to actually see if it helps change behavior and incorporate into future skin cancer screenings because when you screen that population, the risk, or the likelihood of someone having something at that age is pretty low. 

But the importance is giving -- getting them aware and educating them so that they change their behavior, so we're hoping that this is a device is something that we can use. And actually we've used it on some adults and they love it because you know it gives you an idea of what's actually going-on on your skin. And then again, the self-tanners as I stated is a 3 -- 5% dihydroxyacetone. It's just a stain and it does come off in a few weeks. If you're gonna do it for yourself make sure you wash your hands thoroughly after use. I've had patients forget and their palms are bright orange, so wash your hands.

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