Skin Cancer and Psoriasis
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Shiva: My name is Shiva Mozaffarian and joining me for a discussion about skin cancer and psoriasis is dermatologist and Professor of Dermatology at the University of Pittsburgh, Dr. Laura Ferris. Dr. Ferris practices general medical dermatology with a special focus on skin cancer and psoriasis. She also directs the UPMC Clinical Trials Unit in the Department of Dermatology where she has served as principal investigator on over 100 clinical trials primarily in the area of psoriasis, atopic dermatitis, melanoma and skin cancer.
Shiva: Welcome Dr. Ferris! Thank you for taking time to be on Psound Bytes™ today. This time of year, everyone wants to spend more time outside in the sun whether it’s near the water or just having fun with family. However, there are risks associated with being in the sun. Can you address what some of those risks are especially if the skin is not protected from the sun’s UV rays?
Dr. Ferris: That's a great question and it is an important concern this time of year. I think it's really healthy for everybody to be outside, but the sun's UV rays do cause some problems for us. The two big problems that we see are number one, aging, so getting wrinkles, getting kind of bad skin texture, or hyperpigmentation of the skin where we get darker blotchy spots. And then of course, the one that I worry about the most as a dermatologist is the risk of skin cancer. Kind of tied in with all that is the risk of sunburn. So, sunburn is uncomfortable when we get it. It tends to be temporary. Most people get through it, but we know that having sunburn puts you at risk for having more aging and also higher risk of getting skin cancer.
Shiva: So, you mentioned sunburn and skin cancer. What is the damage caused by a sunburn (how deep does it go) and can you elaborate more about what skin cancer is?
Dr. Ferris: So yeah, sunburn is basically the damaging effect of UV rays and most of the damage is in the keratinocytes which are the cells that make up the skin and if we look, we can see that the sun will actually cause in some cases death of the keratinocyte so it can make them die. It can also cause DNA damage within those and really that is sort of the hallmark of cancer is that you have genetic changes inside a cell. So, genes that get altered or mutations which are sort of changes in genes that can be harmful that occurs as a result of the sun. However, you also do get damage that occurs a little bit deeper down. So, if we think about sort of the structure of the skin and the collagen, that is what makes our skin look more youthful and retains water so our skin looks kind of more plump and filled out. That can also get damaged by the UV rays as well. Now skin cancer or skin cells are keratinocytes or skin cells generally, or the melanocytes or pigment producing cells that kind of go awry and they start to divide too quickly and they don't die when they should. So, skin cancer is basically uncontrolled growth of cells within the skin that ultimately can just grow and become big lesions in place, but also can break off and spread.
Shiva: Thank you for that explanation. And what are the typical forms of skin cancer?
Dr. Ferris: So, there's several different types of skin cancer, but we really focus on the three big ones and those are melanoma, basal cell carcinoma and squamous cell carcinoma. Melanoma is a tumor of the melanocytes, which are the pigment producing cells in the skin. It is the least common of those three, but it's really the most deadly. So, melanoma can grow, usually starts out as a dark spot on the skin. Although it can sometimes be red or pink and we usually look for a spot that's growing or changing. Sometimes we say we look for the ABCD’s. “A” is asymmetry, so that if you cut the lesion in half, the two halves are different from each other. “B” are borders or edges that are irregular. “C” is color, so either multiple colors or a darkening color, or a color that's different than the other moles on your body. “D” is the diameter or width of it. So, particularly lesions that are bigger than a pencil eraser. And then sometimes we throw in an “E” which is evolving or changing lesions. So, melanoma is something important that we want to detect early. It's very treatable when it's found in early stages, but if it's left untreated, some will grow and they can then metastasize or break off and travel to distant parts in the body. And that's when they can become deadly. The next one that we'll talk about is basal cell carcinoma. That is the most common cancer really of all of humankind. So, there's certainly the most common skin cancer. It is estimated that most people, if they are of fair skin types and they live into their 70s, a very large number of those patients will develop basal cell carcinoma at one time or another. It's usually a pink bump or sometimes a pink scaling patch that may bleed with just a little bit of trauma, very treatable when it's found early. It's very rare for these to get big and cause significant problems or even death, unless they're really left undiagnosed and untreated for years at a time. And then the third one that we'll talk about is squamous cell carcinoma. This is usually a pink or red scaling spot on the skin. Also, like basal cell carcinoma can bleed with very little trauma. These are less common than basal cells, but more common than melanoma. Most of these are found early and they can be treated. However, these have a little more potential to become aggressive and to metastasize and cause problems. The patients that we really think about it being at high risk of having bad outcomes from squamous cell carcinomas are patients who are immunosuppressed. So, patients who are on medications that strongly suppress the immune system, the population that we see that in the most are patients who have had organ transplants. So, patient who’s had a kidney or lung or liver transplant has to be on medications to prevent the immune system from rejecting their new organ. Those medications also put you at increased risk of skin cancer, so our body's immune system doesn't just protect us from infection, it helps to protect us from cancer too. So, when the immune system notices that cell doesn't look right, something's changed. Oftentimes, the immune system will actually clear it away before it becomes a noticeable cancer.
Shiva: Interesting. So, how would someone know if it's skin cancer versus psoriasis? Are there any clues or is it possible to confuse the two, or even have both at the same time?
Dr. Ferris: So, that's a great question. You know it is possible to confuse the two. So, I described basal and squamous cell carcinomas as sometimes being red and scaly. And as your listeners know, psoriasis tends to be red and scaly. We do see patients who have both. It can be confusing. In general plaques of psoriasis tend to be on the larger side, whereas early basal or squamous cell carcinomas are smaller, they may be less than half an inch across. Although they can get bigger and become even harder to distinguish. The other thing that's interesting is that sometimes you can develop a skin cancer within a plaque of psoriasis. So, one of the ways that we occasionally find basal cell or squamous cell carcinomas in psoriasis patients is after they start an effective therapy and the plaques go away and we may notice that there's one or two pink scaly spots that are left where there used to be a plaque and, we may think well, maybe that's just a little bit of the psoriasis left, occasionally it's actually a skin cancer that was sort of hiding in a plaque.
Shiva: Definitely good to know. So previously you mentioned people who are on immunosuppressive medications. Is there any evidence that suggests people with psoriasis are more likely to get skin cancer? What factors place someone at higher risk for skin cancer?
Dr. Ferris: So that's a really important question and it can actually be a hard one to answer. So, one of the things that happens is that patients with psoriasis tend to see dermatologists, and dermatologists tend to look for and find and diagnose skin cancer. So, there's probably a little bit of an association of if you see a dermatologist often enough, you're more likely to be diagnosed with an early skin cancer. So, that's one thing. But we also know that there's unique things about how we treat psoriasis that do increase the risk of skin cancer. So, the sun, as we talked about at the very beginning or UV light is a major risk factor for developing skin cancer. So, as your listeners probably know, one of the therapies that we have for psoriasis is UV light therapy. It may be narrow band UV light given in a doctor's office or PUVA, which is psorolin plus UV light. So, we have psoriasis patients who we are actually intentionally giving UV radiation to. So, that may be increasing the risk of skin cancer or we have patients maybe who before we had all the therapies, we have now had years of PUVA which has the highest risk of inducing skin cancer. And then as you get older your risk of skin cancer goes up. So, if you're a patient has had psoriasis for a lifelong, you've had 50 PUVA treatments over your lifetime. You've also had normal sun exposure and now you're hitting 65, 75 years old, which is where your risk of skin cancers increase. You can kind of get the perfect storm where all these things come together. Also related to UV light, a lot of patients note on their own “hey, if it's the summer and I'm out in the sun a lot, my psoriasis is a lot better.” So sometimes patients with psoriasis will intentionally get extra UV light as a way to try to get their psoriasis to get better. And then finally we have drugs that we give patients that can be associated with skin cancer risks. So, like I mentioned in our transplant patients who get immunosuppressive drugs, an example of this would be cyclosporine. Well as we know cyclosporine also treats psoriasis. So oftentimes our patients will have had immunosuppressive drugs like cyclosporine and that can increase the risk of skin cancer. Other drugs probably can slightly increase the risk not to the extent that UV light does, or like cyclosporine does, but depending on the studies you read, there's some evidence that there may be a slightly increased risk of melanoma with methotrexate and then also with the TNF inhibitors. So, the drugs that we look at are like adalimumab or infliximab. Some studies have suggested that there can be an increased risk of skin cancer with these drugs as well.
Shiva: Given the risk factors you just mentioned, I’m curious is genetics considered a risk factor?
Dr. Ferris: Genetics do increase the risk of skin cancer, but primarily for melanoma. So, if a patient has what we call a first degree relative, a parent or sibling who's had melanoma, then they are at increased risk of developing melanoma too. The genetic risk for basal and squamous cell carcinoma is not quite so clear. If a patient has had for perhaps several family members with melanoma, we often times will recommend that they get screened regularly because we know that they are at higher risk.
Shiva: And how is a diagnosis of skin cancer made? Is a skin biopsy needed?
Dr. Ferris: In general, a skin cancer diagnosis is made when a dermatologist examines your skin and finds a lesion that makes them think twice so that they're suspicious might be a skin cancer. If we are suspicious in most cases, we will do a skin biopsy and that is to get either a piece of that potential skin cancer, and if we think it might be basal or squamous cell carcinoma, or if we think it's a melanoma, we actually do a biopsy that lets us get the entire lesion off. And then that is sent out to be looked at under the microscope by a pathologist.
Shiva: And how critical is it to see a doctor for diagnosis of skin cancer?
Dr. Ferris: It’s important to see a doctor to get a diagnosis because really, if you suspect you have a skin cancer, you really need that biopsy. And then generally the first line of treatment is to have that lesion be excised or to have surgery. And most cases can be done in the dermatologist’s office. But you need to start the process, so you need to get the right diagnosis, which means having a doctor say is this truly a potential skin cancer to do the biopsy and then to get the right diagnosis by having our pathologist’s look at it under the microscope.
Shiva: And should someone be diagnosed with skin cancer, what are the treatments options?
Dr. Ferris: So, most skin cancers can actually just be treated in the dermatologist’s office, most commonly with an excision under local anesthetic. We numb up the area, cut out that area and then put in stitches and that can be done while patients are awake. You don't need general anesthesia. You don't need to be sedated and it's an outpatient procedure. You go home after you're finished, and then you may come back for a check on the wound or to get sutures removed a week or two after the surgery. Sometimes we need to do more specialized skin cancer surgery. One form is called Mohs surgery, which was named after Dr. Frederick Mohs, where the surgeon actually acts as pathologist too. So, they take out the visible tumor, freeze it, stain it, and look at it under the microscope and then clear out with the least amount of normal healthy skin removed, get rid of that tumor so that they have the smallest hole or defect and then can close that up and give the best scar. So, this is great if it's in the middle of the face, or if it's up against the eye, or if it's hard to just remove it. But most skin cancers would be treated with excision in the office. That goes for most melanomas too. However, melanomas that are thicker or sort of more advanced, often do need to be treated with a bigger surgery in the operating room. And for any of the skin cancers that are more advanced, maybe that have spread beyond the skin or are particularly large and can't just be removed with surgery, we will often times send our patients to oncology. So, there are chemotherapy and what we call immunotherapy drugs that can be used to help treat more advanced skin cancers.
Shiva: So, you mentioned the use of phototherapy with UV light earlier. We’ve heard some people use the sun to help control their psoriasis. Is this an effective method compared to other therapy options?
Dr. Ferris: The problem with using the sun is you don't have a measured dose. So, you're kind of guessing at how much sun you're getting. And so, there's a risk of sunburn. You know, if you go outside on a cloudy day, you might not feel like you're getting burned or you might not be getting hot and sweaty so people can end up getting more UV light than they intend. So, you can't really measure what you're getting from the sun. The other thing is that it's harder to protect areas. So, if somebody gets phototherapy, for example, if they have psoriasis on their hands and feet, we can just give the therapy to that area. Or if we're using a laser that gives ultraviolet light, we can just focus it on the psoriasis plaques. Or even, if we're in a phototherapy booth, we can cover the face. We can protect the eyes. You really can't do that if you're sitting outside in the sun.
Shiva: Right, and use of tanning bed is not a viable option either, correct?
Dr. Ferris: Right, so tanning booths, we don't like those. We know that they have been shown to be associated with increased risk of skin cancer. Again, they're not regulated. So, you don't know when they've changed the bulbs and the amount of UV light you're getting is higher. You're also limited and it can be hard to cover certain areas. You don't have a physician monitoring you to say when have we gotten too much? When do we need to go up? When do we need to go down? So, in general we do not recommend tanning beds as a treatment for psoriasis. Plus, we just have so many other more effective, less dangerous therapies.
Shiva: Absolutely! And are there any treatment cautions people with psoriasis should take when they're in the sun?
Dr. Ferris: So, there are some treatments for psoriasis that we do caution patients will make them more sun sensitive. So, the big one is acitretin that is a retinoid and we know that that actually does make patients more susceptible to sunburn. So, for example, if normally you could go out in the sun for 30 minutes and not burn, that may be reduced to 15. So, we do recommend that patients are careful with the sun if they're on acitretin. Also because of the significant increased risk of skin cancer with the use of cyclosporine. I also counsel patients who are on cyclosporine to be careful not to get excess sun exposure because we don't want to increase the risk of skin cancer. So, cyclosporine won't increase your risk of burning, but it increases your risk of cancer. Acitretin will increase your risk of burning in the short term.
Shiva: And if skin cancer is left untreated, what are some of the risks?
Dr. Ferris: Skin cancer is very treatable when it's found early. The risk is particularly for melanoma and squamous cell carcinoma to some degree. The risk is that if you leave that tumor there and it continues to grow that it will grow deeper. It will do things like invade into the underlying muscle or even bone if it's left long enough. Or it will metastasize or spread to the lymph nodes in the area, or even distantly, to organs. So once a skin cancer is spread, we can't just treat it with surgery. That's when we have to start thinking about other therapies. These have a lot more side effects, they've got more risk. The best way to treat skin cancer is to find it early and remove it early with a simple procedure in the office.
Shiva: So, are there any other preventative steps someone can take to avoid skin cancer?
Dr. Ferris: The most important thing people can do to prevent skin cancer is to be careful not to get a lot of ultraviolet light exposure through sunscreen, sun avoidance, sitting in the shade, wearing the right clothing. Wear sunscreen if you're going to be out in the direct sun and you've got uncovered skin. But also remember sunscreen is totally safe to be used on psoriasis. You can apply it or spray it right over the plaques. You may find that you like the feel of one sunscreen better than another. So, look for something that is at least SPF 30. And if you're really gonna be outside a lot, SPF 50. Reapplying it about every 90 minutes or after you go swimming or after you sweat a lot. So, that's something that patients can do. But the other thing I tell everybody is sunscreen isn't your only option. If you're gonna be out walking around, wear a hat. It will help to protect your scalp. It will if you have a wide brim help to protect your face. If you have the option of sitting in the shade or sitting in the sun, sit in the shade. That makes a big difference. So, you could go to the pool or the beach and sit under a nice umbrella and really get very little UV light as long as you're under there. Wearing sun protective clothing. So, clothing over the skin really does help to block most UV light, and there's very good, very available UV protective clothing. So, if you look for this you can find it in stores or you can order it online. And so, wearing that, if you have a UV protective shirt on that is actually preferable to wearing sunscreen. So those areas covered by the clothing are very well protected. The other things that are important to do are to look at your own skin so that if you do have a spot that is maybe growing, looks funny, it doesn't look like other spots on your skin or is bleeding with very little trauma. Make sure that you don't ignore that. So, that's really not necessarily preventing it, but it's increasing the early detection. Other things that patients can do are to talk to their doctor. If they've had maybe two or three skin cancers, there's certain blood pressure medicines for example, that might increase your risk of getting more skin cancers. So, I will sometimes talk to patients about switching to a medication that doesn't put them at high risk for getting another skin cancer.
Shiva: Great recommendations! This has been such an interesting discussion about skin cancer. I hope our listeners will take the information you've provided and use it to reduce their risk of skin cancer. So, thank you Dr. Ferris! Thank you for being here today. So, in closing, do you have any final advice you'd like to share with our listeners about skin cancer and psoriasis?
Dr. Ferris: I think the final piece of advice that I would give is that summertime is a wonderful time. Go outside, get exercise. That's important for everybody. It's particularly important for psoriasis patients. Enjoy your time but just be careful. There's no such thing as a healthy tan. There's certainly no such thing as a healthy sunburn. You can enjoy the outdoors safely with a few steps to protect your skin.
Shiva: What a great message to end this episode. Thank you, Dr. Ferris, for providing such great advice about skin cancer and most of all how to prevent it! For more information about psoriasis, psoriatic arthritis and treatment options contact our Patient Navigation Center by calling (800) 723-9166 or by emailing firstname.lastname@example.org. And finally, thank you to our sponsors who provided support on behalf of this program activity through unrestricted educational grants: Amgen, AbbVie, Bristol Myers Squibb, and Janssen.
We hope you enjoyed this episode of Psound Bytes™ for people with psoriasis and psoriatic arthritis. If you or someone you love has ever struggled with psoriatic disease, our hope is that through this series you’ll gain information to help you lead a healthier life and inspire you to look to the future. Please join us for another inspiring podcast. You can find this or all future episodes of Psound Bytes™ on Apple Podcasts, Spotify, iHeart Radio, Google Play, Gaana, and the National Psoriasis Foundation web page. To learn more about this topic or others please visit psoriasis.org or contact us with your questions or comments by email at email@example.com.
This transcript has been created by a computer and edited by an NPF Volunteer.
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