Tanning Beds Increase Skin Cancer Risk
Aug. 20, 2009 – Ultraviolet light, whether from the sun or from a tanning bed is a known carcinogen, yet millions of Americans still seek the glow of a “healthy tan”. In this edition of Cancer Connection, Lynn Cornelius, MD, explains the effect of tanning on a person’s risk for melanoma and other skin cancers, discusses how melanoma is diagnosed and explains the challenges of treating the dangerous disease.
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TRANSCRIPT OF AUDIO FILE
On this edition of Cancer Connection, we’ll talk about skin cancer, including prevention, treatment and the role tanning plays in the process.
Host: Thanks for downloading this podcast from the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St Louis. I’m Jason Merrill. The World Health Organization recently said tanning beds can be as deadly as arsenic or mustard gas, increasing the odds of skin cancer by 75 percent. While this shouldn’t come as a surprise, many not only still tan, but they also equate tanning with good health. To talk about skin cancer awareness with us is Lynn Cornelius. She is chief of dermatology at Washington University School of Medicine. Dr. Cornelius, thank you for joining us.
Cornelius: It’s my pleasure to be here.
Host: Were you surprised by the World Health Organization study on tanning beds?
Cornelius: I was not surprised in the least, and actually there are a couple reasons for that. There’s been a lot in the literature regarding ultraviolet light and the link to skin cancer – very strong evidence. And we know particularly in many of our younger patients that patients who do abuse ultraviolet exposure, either in solar radiation or in tanning beds, we know that we tend to see these patients at a younger age for their skin cancers. There’s also evidence in the literature from animal models that the skin at an early age is incredibly vulnerable to ultraviolet light. You can take mice and expose them to ultraviolet light at a very early age (neonatal mice), and those mice will develop melanomas. There are some other genetic alterations that the mice have. Whereas the same mice exposed later in life tend to develop different types of tumors. In addition to that, we know that the number of moles or nevi that patients have, if there is a high number, that puts them at risk for the development melanoma. The corollary to that is that the more ultraviolet light you get in childhood, the more moles you get.
So there was a lot of various circumstantial as well as evidence-based medicine in the literature, and what the World Health Organization did was a meta-analysis of many of these research articles and epidemiological articles. They took things that they could put together in one comprehensive statement and came up with this conclusion.
Host: There seems to be a feeling by many who tan that it makes them look healthy. The newspaper article the other day had a fellow that said, “I want to look healthy. Nobody wants a pasty-looking consultant.” However, I don’t think anybody wants a consultant with a massive scar on their face from a melanoma removal. So talk about why tanning isn’t healthy.
Cornelius: If you look at the history of tanning, it’s very interesting. And probably back in the twenties or thirties was when tanning came into vogue as looking healthy or actually an indication of wealth. And that was with Coco Chanel, who went away on some winter vacation to some sunny area and came back tan. Before that time, many people probably know, it was better and showed higher socioeconomic status if you were in fact pale-skinned and didn’t have a tan because darker skin or tanning meant that you had a lot of outdoor labor. That was not a good thing. So since that time in the twenties and thirties, it’s kind of been propagated that if you have a tan, you’re healthy, you’re wealthy, you’re outdoor having a lot of outdoor activities.
It’s really, if you look at what tanning is, it’s the body’s defense against or attempt to protect you from ultraviolet exposure. So what happens in the skin, there are pigment cells called the melanocytes, and those are the cells that are the precursor to melanoma. When you get ultraviolet exposure, those pigment cells are prompted to produce melanin or pigment. And when they produce more pigment, that pigment gets distributed amongst the nonpigment cells in the epidermis to protect those cells. The very interesting fact is where that pigment gets distributed is above the nucleus of these other cells, where the DNA is harbored. So it truly is the body’s attempt to protect all the cells in the skin from the ultraviolet exposure. It is absolutely not healthy.
Host: You touched on this earlier. Why is it important to get the message out to younger people about their risk of skin cancer not only from tanning beds but sun exposure in general?
Cornelius: I believe – and the literature does substantiate this – that the damage that you incur early on as well as later but particularly early on, I think, for melanoma, your skin is probably at a much more vulnerable state when the melanocytes are younger. A case in point: The development of nevi or new moles. Younger people, not just with skin cancer, tend to feel that these types of behaviors, these high-risk behaviors, may have consequences for them 20 or 30 years down the road and that there will be a “cure” by the time they develop the disease. I can tell you that in melanoma, we have not changed our treatment probably in the last 40 years. So people and young people are dying of the disease.
Host: Can a person’s risk for developing skin cancer decrease over time?
Cornelius: Studies have shown that the use of sunscreens over time will decrease a person’s development of what are called actinic keratoses. These are, people like to call them precursors of skin cancer, not melanoma, but squamous cell and basal cell – other forms of skin cancer, the less serious forms. But if a person uses sunscreens regularly, their incidence of developing these precancers on the skin does go down.
Host: What should people look for on their skin that should tell them they should see a dermatologist?
Cornelius: So we try to teach people many things. One the simplest things is the ABCDEs of melanoma. I think that’s an easy thing for people to remember. The letters stand for the initials of the first word of what you need to watch out for. A is for asymmetry, so if a mole or a pigmented lesion on your skin looks a little bit asymmetric. In other words, you can’t divide it into four quadrants and have each quadrant look the same. B stands for border, or border irregularity, which means that if the edges of the mole are very jagged or irregular, that’s another tip-off. C stands for color. Moles should be, for the most part, pretty evenly colored or pigmented. If you have multiple different colors within a mole, then that is one of the warning signs. D stands for diameter. We have taught people that a diameter greater than the tip of an eraser head, which is 6 millimeters in size, if a mole is greater than that size or develops to be greater than that size, then that’s another warning signal. I can tell you that we’ve diagnosed many melanomas, early melanomas, that are much smaller than that size, but it’s a good rule of thumb. And the last is E or evolution, which means that a mole that is changing or a brand-new mole that looks a little bit unusual according to those other characteristics. Those are important. Those are the ABCDEs of melanoma. For the nonmelanoma skin cancers, the basal cells and squamous cells which are more common but tend to be a little less serious, lesions that don’t heal, bleeding, something new that is crusty that tends not to go away within a short period of time.
Host: How dangerous is melanoma?
Cornelius: Melanoma is the most serious type of skin cancer of the three most common types: basal cell, squamous cell and melanoma. And melanoma can be fatal, particularly if melanoma spreads to other parts of the body. So it is the most common type of skin cancer that can spread to other portions of the body, including the lymph nodes, the brain, the lungs, the liver. If in fact it does spread, if it’s not caught early and treated surgically, when you have your greatest chance of cure by a surgical excision, and it spreads to these other areas of the body, the types of chemotherapy that we have are not particularly effective.
Host: Earlier you said your treatment of melanoma hasn’t changed at all over the past 40 years. What is the treatment in general?
Cornelius: So as I alluded to earlier, the treatment for early melanoma – which means melanomas that are very thin or caught at a very early stage – is surgical excision. And when melanomas don’t have an invasive portion, when they don’t penetrate to the deeper layers of the skin, when they are what we call in situ, we perform what’s called a wide local excision, which means you cut around the skin of the melanoma. We also do that for melanomas that are invasive, which means that they are penetrating into the deeper portions of the skin – the collagen, the blood vessel area, the lymphatic drainage area and sometimes the subcutaneous tissue. When they are deeper, we also employ wide local excision but sometimes in conjunction with checking the lymph nodes by doing what’s called a lymph node biopsy. In that case, if the lymph node biopsy is positive in those deeper melanomas or if the patient has lymph node disease at the time of diagnosis or widely metastatic disease, that is when the chemotherapeutic agents are employed.
If melanoma spreads to the lymph nodes, typically the basin of that lymph node – it may be the axilla or the arm pit area, the inguinal area – is totally excised. If we have evidence either by the microscope or by clinical exam that that area is involved, we’ll do what’s called a lymph node dissection, and that patient may be a candidate to have what’s called interferon. Interferon therapy is a yearlong therapy that is a fairly difficult agent to take. It makes you feel like you have the flu. You have flu-like symptoms. And it’s so difficult to take sometimes that in older individuals that have this stage III disease or melanoma that’s spread to the lymph nodes, people elect not to have it because the efficacy evidence is fair. It’s a benefit/risk type of thing. The patients end up having lots of side effects. So that’s when the patient talks to the oncologist and weighs the benefit and risk.
If in fact the melanoma has spread to other areas of the body – the brain, the liver – then other therapeutic agents are employed. The FDA-approved agents are not particularly effective as well for melanoma that has systemic involvement. However, we’re fortunate at the cancer center to have clinical trials available to our patients that are newer vaccines and newer available agents that hopefully in the long run will prove to be more efficacious in the treatment of metastatic disease.
Host: Overall, what’s the message you want to get out to people about skin cancer risk?
Cornelius: I think people need to recognize that both solar ultraviolet light and tanning bed ultraviolet light are dangerous. They are known carcinogens. The tanning beds can be even more dangerous than sunlight, in particular because some of the tanning beds employ what are called high-pressure UVA lights, ultraviolet-A lights, where they deliver a higher amount of ultraviolet exposure in a shorter period of time. So those things are very important to know and to know the risk of ultraviolet exposure. Ultraviolet is a known carcinogen. There’s been a lot of hype about getting vitamin D through ultraviolet light and that it’s important to get vitamin D, which in fact is true. But the point that I think most dermatologists would like to drive home is there are very safe ways of getting vitamin D – in food, in supplements – and there’s no need to rely on ultraviolet light to get your vitamin D.
Host: Dr. Cornelius, thank you for joining us.
Cornelius: It’s been my pleasure. Thank you so much.
For more information about skin cancer, visit the Siteman Cancer Center online at www.siteman.wustl.edu
or call 800-600-3606. Thanks for downloading. Until next time, I’m Jason Merrill.