Skin Cancer and Sun Safety

Adult hand applying suscreen to little girl's nose

Are you on good terms with the sun?  Do you know the difference between UVA and UVB rays?  In the summer months especially, we all need to be aware of the risks we take spending so much of our time outdoors.  And while we hear a lot about the importance of sunblock, knowing what to use – as well as how much and how often to use it – can be confusing.  This episode of Total Health Radio answers your questions about protecting you and your family from the long-term dangers of the sun – and offers advice on what symptoms to watch for in order to catch and treat skin cancer in its earliest stages.

About the Guest
Amy Reisenauer, MD, is a dermatologist with Kaiser Permanente in Hawaii.

Episode Host
Farra Levin communicates for a living at Kaiser Permanente, and she loves talking about health topics and issues. Her passion comes through in her interviews – along with her humor and straight-talking attitude. Read more about Farra.

Learn More
Interested in learning more about how to protect yourself and your family from the sun’s harmful rays? Check out these resources:


FARRA: Welcome to Total Health Radio. I’m your host, Farra Levin.  We know this is the time of year when most of us are looking forward to spending that much-needed time in the sun.  And though we might not want to acknowledge it, our time on the beach or in the tanning bed can even have serious consequences.  Dr. Amy Reisenauer is a dermatologist with Kaiser Permanente in Hawaii. She’s here to give us the facts about skin cancer and teach us how to stay safe in the sun.  Thanks so much for joining us.

DR. REISENAUER: Thank you for having me.

FARRA: So let’s start with, how common is skin cancer?

DR. REISENAUER: You know skin cancer is actually incredibly common.  One in five Americans will develop some form of skin cancer during their life, and melanoma which is the most serious form of skin cancer, claims the life of one American every hour.  So it’s a big problem.

FARRA: Do you find that it doesn’t matter what age you are, you’re seeing skin cancer in people of all ages?

DR. REISENAUER: We are seeing skin cancer in younger and younger patients.  Melanoma is now the most common form of cancer for young adults age 25 to 29, so the most common form of cancer period.

FARRA: So you mentioned melanoma and I’m going to say I’m completely ignorant because I thought that was the only form of skin cancer. So what are the most common forms of skin cancer?

DR. REISENAUER: There are actually several forms and thankfully melanoma, which is the most serious type, is a less common form.  The most common are basal cell skin cancer and squamous cell skin cancer, which do not normally spread to other parts of the body and have the type of consequences that melanoma can have.  But, basal cell and squamous cell skin cancers still need to be removed because they are cancer, and they will keep growing in an unregulated fashion if you don’t take care of them.

FARRA: I’m assuming the sun is the main reason for the way that people get skin cancer, but how does the sun or use of a tanning bed increase your risk of skin cancer?

DR. REISENAUER: Well it’s the ultraviolet rays from the sun that increase the risk of cancer and what the ultraviolet rays do is they actually cause damage to the DNA of your skin cells. And if your skin cells accumulate enough DNA damage, they turn into a cancer cell.  And ultraviolet radiation is used in tanning beds.  It was thought sort of in the olden days that tanning beds were safer because they used ultraviolet A rays instead of UVB. But now we found out that UVA rays are just as dangerous as UVB and they are cancer-causing as well. So tanning beds are not safe at all.  Ultraviolet radiation and tanning beds has actually been declared a carcinogen.

FARRA: What would you say that people who say that a certain amount of exposure to the sun is a great way to get vitamin D?

DR. REISENAUER: You do get vitamin D from the sun, but you can also get vitamin D really safely by taking an oral supplement.  So taking vitamin D orally is a great way to make sure that your body is getting enough without putting yourself at any risk of skin cancer.  It really does not take that much time in the sun to get damage to your DNA. Even going out for 20 or 30 minutes without protecting your skin can cause some problems.

FARRA: For the second little piece, I want to do a sort of myth busting with you.  I’m going to ask you a question, and let me know if it’s myth or fact.  Men and women with darker skin tones can’t get skin cancer?

DR. REISENAUER: That is a complete myth.  People of all skin types and skin colors can get skin cancer, and in fact I tell my patients that Bob Marley died of melanoma. It is something that everybody has to be aware of.

FARRA: Myth or fact: sun is blocked out by the windows of your car?

DR. REISENAUER: It turns out that the windows of your car do block out UVB rays but they don’t block out UVA. As I mentioned the UVA rays are dangerous and can cause skin cancer, so you are not protected just by the car window.

FARRA: Okay. This is one actually as a parent I’ve heard a few times, especially with sunscreen and your children. Myth or fact: sunscreen causes skin cancer?

DR. REISENAUER: That is a myth and there have never been any scientific studies that have shown that sunscreen causes skin cancer.  There are different types of sunscreens out there and there are some sunscreens that are chemical-based and there are some sunscreens that are physical blockers.  There have been some chemical ingredients in sunscreen that has been proven to be unstable over time in the sun and they can degrade.  So a lot of people like the idea of the physical sunscreens that just stay on the surface of the skin and reflect the sun’s rays and block the sun without getting absorbed into your system. So sunscreen does not cause skin cancer.  There are some chemical sunscreens that are less stable than others and so if you want to really avoid that issue completely, you can go with a physical blocker that contains zinc oxide or titanium dioxide or both as active ingredients.

FARRA: Myth or fact: if I put sunscreen on in the morning, I’m ready to go all afternoon?

DR. REISENAUER: Unfortunately this is a myth because sunscreens do not last all day. The ideal reapplication for all sunscreens is every two hours and that’s where a lot of people fall down.  Because most people remember to put it on in the morning before they leave the house, but then as the day goes on, they’re running their errands, they’re driving in their car, they’re not thinking about all of the incidental sun exposure that they’re getting throughout the day.  And that morning sunscreen that they put on is long gone.  So you really need to keep your sunscreen with you in your purse, in your car, and reapply it every two hours throughout the day.  If you’re active and you’re sweating or you’re in the water, you really have to reapply it every hour.  And another thing that’s a little bit misleading about sunscreens is if they say waterproof on the bottle, that actually means it’s good for 80 minutes in the water.  Water resistant means 40 minutes in the water.  But it definitely doesn’t mean all day.

FARRA: Do you recommend that people maybe set an alarm on their phone?

DR. REISENAUER: Definitely.  I think that it’s easy to lose track of time when you’re out in the sun and you’re having fun, so setting an alarm, having a system that reminds you to reapply. And whenever the kids are in the water for 40, 50 minutes, just bring them in, pat them down, reapply the sunscreen.  They won’t want to do it but it makes a huge difference.

FARRA: Let’s go into part three, which I like to call, “The dreaded sunburn.”  What’s actually happening to your body when you get sunburned?

DR. REISENAUER: Well when the ultraviolet rays touch your skin and they damage the DNA of your skin cells, it creates this inflammatory response, where your body is reacting to that DNA damage by sending over some white cells and dilating your blood vessels.  So it’s like your body’s emergency stress response to the DNA damage that has happened from the ultraviolet radiation.  So a sunburn is a bad sign.  It means you got enough sun to create this inflammation and you definitely want to avoid sunburns.  Even a sun tan is a sign that damage has happened, because once the acute inflammation from the sunburn goes away and it turns into a dark tan, that’s still a sign that you had damage to your DNA from the ultraviolet rays.  So there’s really nothing healthy about a tan.  It’s like your body’s stress response.

FARRA: And do you find that most people tend to get sunburned when the sun is actually not out, or they tend to forget cause it’s a little cooler weather?

DR. REISENAUER: Yeah that happens a lot because when it’s cloudy, people forget that they need to protect their skin. They think they’re safe but even on a cloudy day about 80 percent of the sun’s UV rays can pass through the clouds. And so you have to wear your sunscreen like normal, even when it’s cloudy outside.

FARRA: Does it matter what time of day you’re out?  I mean I’ve always heard that that sort of 12 to 3 is the hottest time of day, but is that also when you’re at a greater exposure or greater risk of getting a sunburn.

DR. REISENAUER: Yep. The ultraviolet intensity is the strongest between 10 in the morning and 3 in the afternoon, so I try to tell people, limit your sun exposure between 10 and 3.  Of course that seems like the whole day, but if it’s possible to do things outside early in the morning or later in the afternoon, it’s going to be better for you.  The trick with the sunscreens is that when you’re looking at the SPF on the sunscreen – the sun protection factor – that only pertains to its protection against UVB.  It doesn’t tell you anything about the protection against UVA.  So to make sure that you’re getting your full protection, you want an SPF 30 or higher to get the UVB but then you want to check the bottle to make sure it says broad spectrum coverage.  That means it also hits UVA, it blocks UVA.  So most sunscreens that block most will say right on their UVB plus UVA protection or broad-spectrum coverage, something like that.  But you do have to look beyond just SPF.

FARRA: And then how much sunscreen should people be using?

DR. REISENAUER: In order to get the true SPF that’s listed on the bottle, you have to use a lot of sunscreen. A shot glass full of sunscreen believe it or not is what you’re supposed to use to cover your exposed areas.  So your face, your arms, your upper chest, your lower legs.  You need a shot glass full in order to get the true SPF on the bottle.  And it’s pretty rare for people to use that much, so people end up getting a lower SPF than they think they are.  Because it’s just simply not applied thickly enough.

FARRA: Are some groups of people at higher risk for skin cancer?

DR. REISENAUER: Yes, so, fair-skinned people have the highest risk of developing any form of skin cancer.  Even though I mentioned that people with all skin types can get skin cancer, the fairest skinned people have the higher risk. Also people who have red or blond hair or blue or green eyes are at higher risk.  People that have freckling, tend to freckle easily. People with a lot of moles on their body, if they have more than 50 moles especially that puts them at higher risk for melanoma.  If a person has a blood relative with a history of melanoma then they’re going to be at higher risk or if they’ve had any skin cancers in their past, they’re at higher risk for getting another one.

FARRA: And how do people screen for skin cancer at home? What should they do?

DR. REISENAUER: You know the good thing about skin cancer, if there is any good thing about it, is that it’s visible with the naked eye.  You don’t need any special tools to detect it and everybody is really capable of seeing it on themselves if they take the time to look at themselves head to toe, front and back, using a full-length mirror and a handheld mirror if they need to.  But if people just do that once a month, then they’re going to notice if something is changing on their skin.  And so I think that’s my biggest message to get out there, is that people can look at themselves or have a partner to help look at their back and find these skin cancers early when they’re really curable and easy to take care of.  And the scalp is a hard place to check, so I’ve had hairdressers who have found melanomas on patients of mine, massage therapists who have found melanomas on patients of mine.  So engage anyone who’s willing to look at your body physically to help you and a partner, spouse, kid, whoever can look at you at those hard to look at places.  The back, the backs of the legs, the scalp especially.

FARRA: Maybe not appropriate at work, I would think?

DR. REISENAUER: Maybe not.

FARRA: You’ve got to have some sort of relationship to ask a person to do that.  So we talked about screening for skin cancer at home.  What should people be sort of looking at, what are the main things that you tell them to focus on when they see a mole or something that looks a little different?

DR. REISENAUER: So for melanoma –  that’s the most serious type of skin cancer that you want to detect early, and that’s normally going to be a brown or black spot.  Although just to make life difficult, sometimes melanoma can be pink or red.  But usually it’s going to be brown or black and it’s going to be something that’s changing its size, its shape, its color, or maybe itching or bleeding.  Those are the things to look for, and we talk about the ABCDEs of melanoma.  A is for asymmetry, where one half of the spot doesn’t look the same as the other half.  B is for border irregularity where the edges of the spot look kind of notched or smudged instead of smooth and sharp.  C is for color.  If there’s more than one color mixed in like pink, red, brown, black, tan, that’s worrisome.  D is for diameter.  If the spot is bigger than six millimeters, which is about the size of a pencil eraser, then it warrants further investigation. E is for evolution, which is kind of a weird one but it just means change.  If you have a spot on your skin that’s changing or evolving, it should be looked at.  Those are the criteria that we use when we’re checking people’s skin as dermatologists.  For basal cell and squamous cell, these kinds are usually more like pink or red bumps that may be scaly, crusty, scabby.  They don’t heal, they bleed easily. Maybe at first you think it’s a pimple, but then it doesn’t go away and a month passes and it’s still there.  And every time you towel off it bleeds a little bit.  That’s more of the look of a basal or squamous cell.

FARRA: Is there anything else we didn’t cover that you think we should?

DR. REISENAUER: You know I think a message I would like to get out there is that it’s really important that we protect our kid’s skin from the sun because it turns out that 90 percent of our sun exposure basically occurs before age 18. So, it’s the sun that we get as kids that has the biggest impact on our chance of getting skin cancer later.  And there can be a delay between the time when you get your sun exposure or your sunburn and when the skin cancer shows up, and that can be 20 years sometimes, or more.  So it’s the stuff that we do early on in life that can make a big difference and if you get five or more blistering sunburns before the age of 18, it doubles your lifetime risk of skin cancer.

FARRA: Well thank you so much for coming on the show today.  I think we’ve all probably walked away knowing that we should take the sun a little bit more seriously.

DR. REISENAUER:  Yeah, thank you for having me.


This show is for educational purposes only. If you have specific health concerns, you are encouraged to address those with your personal doctor. And as always, if you’re having a health emergency, please call 9-1-1 or go to the nearest emergency department.