A New Study Shows Melanoma Is Highly Treatable If Caught Early, We'll Hear About How To Detect Skin Cancer
May 8, 2012 1:08 p.m.
Dr. Greg Daniels is a medical oncologist, he directs UC San Diego's clinical program in melanoma.
Related Story: Melanoma Rates Increasing Dramatically In People Under 40
CAVANAUGH: This is KPBS Midday Edition. I'm Maureen Cavanaugh. In sunny San Diego, most of us develop a healthy respect for the sun. Among all the benefits to getting out in the sunshine, there are also dangers. One of them is skin cancer. The deadliest form of which is melanoma. This month, there's a push for early detection and prevention of melanoma. And in tandem with that is a new study about melanoma from the Mayo clinic. The headline from the study is that the rate of melanoma among young women and men is much higher now than it was 40 years ago. The reasons for that are apparently complicated and go far beyond the use of sunscreen. I'd like to welcome doctor Greg Daniels, a medical oncologist, directing UC San Diego's clinical program in melanoma. Welcome to the show.
DANIELS: Thank you for having me, Maureen.
CAVANAUGH: Now, we are asking our listener fist they have questions about melanoma, how to decrease your chances of developing skin cancer, how to detect a melanoma. Doctor Daniels, this study found a higher incidence of melanoma in young people. Do we have any idea what it is that we might be doing wrong?
DANIELS: That's an outstanding question. I'm really glad you're bringing this up for two reasons. One is highlighting that increased rate. And so as you point out, the melanoma study documented in young people, a staggering increase in the rate of melanoma. That unfortunately is also happening in less young people.
DANIELS: And across the board, we're seeing an increase. We don't have a good handle on this, obviously, because we've been talking about this for years. There's a good awareness campaign about sun avoidance and sun protection. We certainly can do better on that. But so far we've not been affected on a public health level of stemming this.
CAVANAUGH: You know, as you say, for years, we've been hearing, you know, put on your sunscreen, limit your sun exposure, wear a big hat. You know, do everything you can to sort of limit your exposure to the sun, you know, to a long stretch of exposing yourself to the sun. Have we seen any kind of decrease because people have been taking that kind of advice?
DANIELS: Skin cancer, there's melanoma, which fortunately is less common as a skin cancer. When we talk about sun exposure, there's a direct one to one link in nonmelanoma skin cancers. These are the ones people get on their noses or ears. The more chronic sun damage we get, we see that. And now in 2012, we even see those genetic changes that are driving those cancers and can link it to the direct muto genic effect of ultraviolet radiation, so from a science point of view, it's a nice are is it. We can understand that. It's not as clear of a story yet for melanoma. Absolutely it's related to the sun. And it's related most strongly, it appears, to high intensity intermittent exposures. But when we look at, for example, even the genetics of melanoma, and we now understand it well enough to even develop new drugs that help fight melanoma in the advanced stage, but those genetic changes don't have that same direct smoking gun link. And it brings up other possibilities that sun is causing melanoma maybe in a less direct fashion.
CAVANAUGH: Right. You refer to high intensity intermittent exposures as being linked with an increased rate of developing melanoma. What does that mean?
[ LAUGHTER ]
DANIELS: A good example of that is a tanning bed. And the article that you mentioned brings up this idea that in the younger group, that the use of tanning beds is much higher. So there's an association there between tanning bed usage, which is high intensity intermittent exposure, and increased rates of melanoma. So that would be an example. Another example would be people who live in the northern hemisphere who get August off and go vacation, head south, or even snow birds from Minnesota going down and getting some sun. It's that kind of behavior that's associated with higher rates of melanoma.
CAVANAUGH: Well, that's a question that I did want to ask you. Upon this study from the Mayo clinic was conducted in Minnesota. Isn't sun exposure in San Diego substantially different here than it is in a place like Minnesota?
DANIELS: It's a little bit different. Certainly on the latitude, the proportion of -- and we talk about sun, well, there's lots of radiation coming from the sun, UVA, UVB, UVC, and the ratio of these damaging rays changes on the latitude where you're at. So it is true that that ratio of UV will change, are the intensity will change. But when I was recruited to San Diego, Greg, you have to come to San Diego, it's so sunny, we have so much melanoma. Unfortunately, places like Connecticut, half the sunny days, have a similar incidence of melanoma as sunny San Diego. So I wouldn't hold it against San Diego that we have a lot of sun here. I love it here.
CAVANAUGH: Well, that mystifies me though. Is what you're saying that a place like as you said, Connecticut, or some northern state wouldn't perhaps have as many overall skin cancers as we get here in San Diego in but they would have a similar incidence of melanoma?
DANIELS: If you look at these incident mappings there is a general smile across the U.S. there is a latitude difference in skin cancers. But it's not huge, and it really also reflects the ethnicity of the population because the incidence proportion to how easily you sun burn. So if you have somebody with a darker pigmentation, and they don't get that inflammatory response to the sun, their rates and incidence of melanoma is lower. So you have to look at the population. That's where these maps are a little hard to interpret sometimes.
CAVANAUGH: So we're on -- it's no spike here in San Diego. We're on an average across the country?
DANIELS: Yes. A good example of this is Australia. So there's a bunch of people down there that biologically shouldn't be there.
CAVANAUGH: Yes, right
DANIELS: There's a lot of northern European, easy to burn kind of skin living down in a very sunny place. And their lifetime incidence of melanoma approaches 1 in 20.
>> Which is huge. So the idea is that some of the driving force behind the melanoma incidence is that biologically, we're living in some different latitudes than our skin may be adapted to.
CAVANAUGH: I see.
DANIELS: So some of it may be that.
CAVANAUGH: Elizabeth from San Diego, welcome to the show.
NEW SPEAKER: Hi, I've been listening to your conversation. I had melanoma 30 years ago. In 1980. I actually got it in -- was diagnosed when I lived in Colorado. But at the time, they were telling me -- the doctors were telling me that melanoma is notorious for metastasizing years later. And I'm wondering if the doctor could please comment on that and if that's the same or if that's changed.
CAVANAUGH: Okay, thank you very much.
DANIELS: That's true. Unfortunately melanoma, once you're given a diagnose of invasive Mel nome Ait changes your life forever. You have to think about your life differently. The Mayo study looked at the younger crowd, and this crowd like yourself was typical. They're thinner melanoma. So thinner just means the depth of invasion, and we measure it in millimeters. So a millimeter is actually significant in melanoma. So a thin melanoma, you have a great chance of curing it. And that's illustrated in the melanoma study. But thins on the other hand have a notorious representation of ten years, 20 years later those 5-10% have it come back in that timeframe. And there because melanoma can spread either through the blood or through limp attics, it can come back anywhere in the body. So it's unfortunately, thin melanomas are cured, but it leaves not just a scar physically, but a scar in your medical life.
CAVANAUGH: And a potential for later problems?
CAVANAUGH: Let's take another call. Renee from Alpine.
NEW SPEAKER: Thank you. Yeah, I'm a wildlife biologist, and I've had street colleagues die of melanoma. And I've been in the sun way too much. I cover up a lot when I go out, but I was wondering if there are any procedure, cosmetic, I don't know, skin peels or something that might help in prevention when you know that you've already spend too much time in the sun.
DANIELS: Yeah, so far no. We don't know any of those. But you bring up a great point. How do you prevent it? As the earlier discussion, trying to figure out why is there such a rising incidence. And so far the best way to present it is to eliminate those things that we can, such as high intensity sun exposure, so covering up like you're doing, with hats, and we may want to talk about this, but the FDA is changing the labeling of sunscreens now to try to make them a little more understandable for people as to what you're actually blocking. So broad spectrum now is well defined as locking both UVA and UVB, and they've set some limits on what can be claimed about it to hopefully preponder people apply these in a more rational way.
CAVANAUGH: As you say, high intensity exposures to the sun have a reputation of being connected with melanoma. Is it that if someone is exposed to the sun on a frequent basis that they have less of a chance of developing melanoma than basically coming from Minnesota to, let's say here, or Florida, and just getting a sunburn once a year?
DANIELS: Okay. So I'll step into the controversy.
DANIELS: A little bit of controversy out there because there are published articles demonstrating that looking at similar crowds, if you get -- looking at lifestyle, such as midwest farmers versus those that are similarly matched but have different occupations, we can look at the amount of sundamage they get based on collagen cross-linking, as a marker for UV damage, and very surprisingly, those people that have evidence of chronic sun exposure, this is not putting on cocoa butter and laying at the pool. But if your occupy takes you out and gives you chronically some level of sun, the rates of melanoma and the death rate were actually lower than those people who had intermittent sun exposure. So it's a good question. We don't know how to apply that on a practical measure, but it's very important.
CAVANAUGH: Pat is calling from Vista.
NEW SPEAKER: I just had a comment and a question. Ten years ago, or 12 years ago, we had a patient that was only 10 at the time, the year before she had been diagnosed with melanoma. No known family history. And so that's even past the ten years, and she didn't go out in the sun any more than an average kid. Didn't do any outdoor sports. And I have a question about, like, all the different sunscreens and sometimes there's sun nanoparticles, plus other chemical aerotones, I don't know if that's a factor with the possibility with melanoma.
CAVANAUGH: Is the question can sunscreens themselves exacerbate one's tendency toward melanoma? Is that how you understood it, doctor?
DANIELS: Yeah, so. People have brought that up. There have been a lot of studies done looking at melanoma prevention and specifically with sunscreens. And the studies are very difficult to do. And they're heterogeneous. So when we apply sunscreen, you bring up a good point, what sunscreen? So some sunscreens just decrease the inflammation in the skin. And that passed as sunscreen before. Or they may just interfere with UVB. So they're very hard to interpret because there are lots of different chemicals used. But when you look at it, there are some studies that the use of sunscreen appeared to be associated with a higher rate of melanoma, there are almost an equal number of studies that say that the use of sunscreens demonstrate les melanomas, and the best study out of Australia is consistent with les melanomas with sunscreen. So it's a difficult one to answer we don't have the ability sometimes to do these controlled studies. All said, sunscreens will help protect your skin. If you're out there, and your about to get a high intensity blast, I would wear a broad spectrum sunscreen. I rely on sun-protective clothing, be hats and pigmented clothing can help particularly with UVA. So there are lots of different strategies. Whether nanoparticles promote different health change, that's really unclear.
CAVANAUGH: So it sounds as if another thing that may be unclear is what about the sunrays may cause melanoma, is that fair?
DANIELS: Yeah, that's fair. It's a question we need to answer. One theory is that the sun comes down, it hits the skin, and especially in these high intensity intermittent, it causes inflammation. We know that as redness.
DANIELS: Yes, it hurts! So that intensity sets up inflammation, and a couple articles came out this year looking at the inflammation appears to be responsible for changing the normal pigmented cell, the melanocyte, and have it migrate up the skin, and start to make these cancerous changes. So that would be an incorrect link of these high intensity exposures, is that it's changing the immune system's look at the skin and promoting these cancerous changes.
CAVANAUGH: This is fascinating. I have to wrap it up though. And since this is melanoma early detection and prevention month, I wanted to ask you, can most medical doctors identify melanoma? Or should you go to a skin specialist if you are concerned about something on your skin?
DANIELS: Yeah. So what should you be concerned about? So the quick answer is you're looking for the ugly duckling. That thing on your skin that's just not like everything else. Or that's changing in some unusual way. We used to rely on the ABCDs of melanoma, that's asymmetry, border irregularity, color variation, diameter. What is more useful, if you have something that sticks out and is changing, get it looked at.
[ LAUGHTER ]
DANIELS: It doesn't have to be a dermatologist, just a provider that can look at your skin. So primary care docs, there's recently an article suggesting that if they did a full skin exam, that the death rate from melanoma could also go down. So talk to your doctor. I would definitely --
CAVANAUGH: You also advocate taking pictures of the moles on your skin and seeing if they change at times.
CAVANAUGH: I have to end it there. Thank you very much.
DANIELS: Thank you.