Maggie McKay (Host): Most people probably know someone who has skin cancer or maybe you've had it yourself. So today, dermatologist, Dr. Dahlia Saleh with BayCare joins us to tell us what we need to know about skin cancer. Welcome to BayCare HealthChat, a podcast from BayCare Health System. I'm Maggie McKay.

Thank you so much for being here today, Dr. Saleh. Let's just start right off with what is skin cancer?

Dahlia Saleh, DO, FAAD: Sure. Thank you for having me. So skin cancer happens when we have an out-of-control growth of the cells that usually live on the top layer of our skin, which is also called the epidermis. And this is usually caused by DNA damage, caused by the sun, that triggers mutations that turn off the signal that make our normal cells stop dividing when we have enough of them.

And then ultimately these mutations make the skin cells multiply quickly and form malignant tumors. What many people don't realize is, believe it or not, it really is the five minutes here, five minutes there of sun exposure that contributes to these DNA mutations. You know, I always say intermittent sun exposure is like spending five dollars every day on a cup of coffee. It doesn't seem like a lot, but at the end of the year you've spent over a thousand dollars. And that's exactly how the sun is. What's also interesting is that the majority of our DNA damage actually occurs before age 40. So oftentimes patients in their 50s, 60s, 70s will present to me with multiple skin cancers, even though they really haven't spent much time in direct sun for several years.

And I always try to explain that cells need to take a certain number of hits to their DNA, before they become cancerous and they were already 80 percent of the way there, 20 years ago. But the good news is the majority of skin cancers are not life threatening and only threaten local structures. But there are a few types that do have the potential to become life threatening that we'll get into.

Host: I always think of that commercial, or it might've been a print ad, I can't remember, but it's emblazoned in my mind for sure, of Brooke Shields, under you know, one of those lights that show all the sun damage because like she has such beautiful skin, but then when you see that image, you're like, oh my gosh, she has a lot sun damage, which probably the average person does too. So I’m always like, put on your sunscreen, put on your sunscreen. And what, like what you said, you think, “Oh, I'm just going out for five minutes, five minutes here, five minutes there,” but it adds up. So what should people look out for and when should they see a dermatologist about it?

Dahlia Saleh, DO, FAAD: So I think it's important to start this off by saying that skin cancer looks different in different people. So depending on your skin tone and the type of cancer, the look of it can vary quite a bit. So the most common types of skin cancer that we see here in Florida are basal cell carcinoma, squamous cell carcinoma, and melanoma.

So starting with basal cells, which are the most common of the three; basal cells often start as what seems to be a pimple that won't go away. They often bleed too. They have a lot of vasculature, so they like to bleed, especially when traumatized a lot. So, oftentimes our patients come to us with a sore that won't heal or a spot on their face that when they shave,it keeps bleeding.

Sometimes basal cell skin cancers are pink and scaly. Other times they're more smooth or pearly or translucent looking. Sometimes they can have a little bit of pigment within them too and appear to be brown. They typically grow very slowly, but the thing about basal cells is that they can be very subtle. And out of all the kinds of skin cancers, I would say these are the most easily missed. Sometimes you can really only see them when the light hits them, right? But when they're more advanced, they are a little bit more obvious.

Now, on the other hand, squamous cell skin cancer, which is the next most common kind that we see here in Florida; these tend to pop up quickly, and they grow much more quickly than basal cells. It's not uncommon for patients to feel like they grew overnight. And squamous cell skin cancers tend to have a larger outward projection. Sometimes they almost look like a volcano with a central core to them. Or they'll look a little bit warty, but these tend to be a little bit more obvious, typically, than squamous cells.

Now, the most aggressive type, which is melanoma, can look several different ways. Typically, melanomas are brown. However, in lighter skin tones, it's important to be aware that you can get what we call an amelanotic melanoma, which is pink, which lacks clinically obvious pigment, and can look similar to a basal cell or similar to a precancer, but they're actually melanomas.

And something to be aware of as well is that we use an acronym, called the ABCDEs of melanoma, that are kind of like little rules of when to present to your dermatologist. And it's important to know too that there are no hard and fast rules.

There are normal skin lesions that break all of the rules of the ABCDEs, so they're more of a screening tool. But starting with A, A stands for asymmetry. So if you were to look at the lesion or the mole and cut it in half, one half wouldn't look like the other half. B stands for borders, a normal mole typically has nice, crisp, defined borders, whereas a melanoma will have fuzzier borders, typically.

C is for color. Normal moles typically have just one color in them, whereas melanomas tend to have more than one color, whether it be pink and brown, or black and brown, or a little bit of a gray look to them with brown. D is for diameter. Anything larger than six millimeters, which is roughly the end of a pencil eraser, should get your attention.

And E stands for evolving or changing. So in general, if anything is growing, changing, not healing, definitely let your dermatologist know.

Host: Dr. Saleh, how is skin cancer diagnosed, and also, how is skin cancer treated?

Dahlia Saleh, DO, FAAD: So skin cancer is diagnosed by taking a biopsy of the lesion that you're concerned about. So we look at something clinically and I would say probably 90 to 95 percent of the time just from looking at it we have a really good idea of what kind of skin cancer it is, but that's not good enough. You know, we always have to know for sure what subtype because each of those kinds of skin cancers, basal cell, squamous cell, melanoma, these all have subtypes as well, and the subtypes determine the treatment.

So it's diagnosed by taking a biopsy of the skin. So what that means is we numb it up, shave it off, put it in the bottle, and send it to the lab. We typically burn the base of the skin, which is called cautery or use a chemical cautery agent to stop the bleeding. And then we send the patient home and wait for the results.

Typically the patient just leaves with a scab, and the only care that's required is Vaseline and a Band Aid and they can still do all of their normal activities. And then we get the results typically in about a week or so. If the biopsy comes back showing cancer, then we have, you know, a lot of different options for treatment.

Host: We know about sunscreen. But how can we prevent getting skin cancer?

Dahlia Saleh, DO, FAAD: The best thing you can do to prevent skin cancer is avoid direct sun, as much as you can. So when you are outside, definitely sunscreen, and I'll get a little bit more into the different types of SPF, but sunscreen, sun protective clothing, hats, sunglasses, sitting in the shade as much as you can. So there's two main types of sunscreens, mineral sunscreen, and chemical sunscreen. Mineral sunscreens contain two very important ingredients; zinc oxide and/or titanium dioxide. These are the ingredients that you really want in your sunscreen when you're looking at the back and looking at the ingredients.

Mineral sunscreens tend to have a little bit more of a white color, so some people kind of shy away from them because they're a little bit less cosmetically elegant than the chemical sunscreens. However, the mineral sunscreens work much better. The chemical sunscreens contain chemicals. So when you turn that bottle over and look at a chemical sunscreen, you'll see long words like octinoxate, oxybenzone, benzophenone, all of those long words that you see. These don't protect your skin as good as zinc oxide and titanium dioxide do.

Chemical sunscreens, however, are a little bit more cosmetically elegant, but they don't do as good of a job of protecting you as the zinc and titanium do.

As long as it's mineral sunscreen, I say 30 SPF or higher is all you need as far as the number goes, as long as you apply every two hours while you're outside.

Also now there's a lot of really good sun protective clothing, and that's rated by UPF. So you want to look at the UPF rating when you're looking at sun protective clothing. A UPF rating, for example, of 30, indicates the fabric of that garment will only allow 1/30 or 3 percent of UV radiation to pass through it.

A garment rated UPF 50 permits only 1/50 or roughly 2 percent of UV transmission. So any fabric that allows less than 2 percent UV transmission is labeled UPF 50 Plus. So I like to say go for SPF 30 or higher as long as it's a mineral sunscreen. And then for the sun protective clothing, go with UPF 50 or higher.

Host: I wish they would bring back that zinc oxide from the eighties that had all different colors of the rainbow.

Dahlia Saleh, DO, FAAD: You can still find it online.

Host: Really?

Dahlia Saleh, DO, FAAD: Yes, you can.

Host: Well, I think now that I'm grown up, if I wore it, it would be a little silly, but I bet it would get teenagers to wear it again.

Dahlia Saleh, DO, FAAD: And I think it's really important, too, about sunscreen. It really is trial and error. So if you just go to the store and pick one mineral sunscreen and try it, you may not like it. And that shouldn't deter you from trying other mineral sunscreens. I mean, I've probably tried 15 to 20 different mineral sunscreens and hate 12 of them and love three to seven of them. So I think it's really important to just keep trying until you find the one that you reach for. And also, any sunscreen is better than no sunscreen. So if you really, like, only want to wear the chemical ones, that's okay. It's better than nothing. But for optimal protection, you want the mineral.

Host: And you wear it, it's the last step if you wear makeup, right?

Dahlia Saleh, DO, FAAD: You can do it under your makeup. It's okay to do it under your makeup.

Host: Oh, okay. See, there's one myth debunked.

Dahlia Saleh, DO, FAAD: Yep. It does not have to be the last step. It's absolutely okay if it's just under your makeup. As long as it's on top of your skin.

Host: Thank you so much. This has been so educational and helpful. And it's always good to be reminded about taking care of your skin because it's our largest organ, like they always say. So don't forget the sunscreen, right?

Dahlia Saleh, DO, FAAD: Absolutely. Thank you. Thank you for having me.

Host: Again, that's Dr. Dahlia Saleh. Head on over to our website at BayCare.org for more information and to get connected with one of our providers. Please remember to subscribe, rate, and review this podcast and all the other BayCare podcasts. For more health tips and updates, follow us on your social channels.

And if you found this podcast informative, please share it on your social media and be sure to check out all the other interesting podcasts in our library. I'm Maggie McKay and that wraps up this episode of BayCare HealthChat. Thanks for listening.