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Melanoma Skin Cancer Risk Factors and Prevention
Dr. K. Wade Foster, MD PhD discusses risk factors for Melanoma, the ABCDE characteristics that are used by dermatologists to classify melanomas, the treatment options, and more importantly, prevention. Learn more about BayCare's cancer services.
Featured Speaker:
K. Wade Foster, MD PhD
Dr. K. Wade Foster received his MD and PhD (biochemistry) from the University of Alabama Birmingham (UAB). He completed both his internship and residency at UAB. Dr. Foster completed his procedural dermatology fellowship at UCLA David Geffen School of Medicine under Dr. Ron Moy and the West Los Angeles V.A. Medical Center. He has been in private practice at Florida Dermatology and Skin Cancer Centers since July 2008. Transcription:
Melanoma Skin Cancer Risk Factors and Prevention
Melanie Cole (Host): Melanoma is the most dangerous form of skin cancer. And here to tell us about it is Dr. K. Wade Foster. He’s a dermatologist, Owner and Medical Director Florida Dermatology and Skin Cancer Center. Dr. Foster, what is melanoma and how is it different from normal skin cancer that people have heard about? Why is it so deadly?
K. Wade Foster, MD, PhD (Guest): Well I think to answer how it is different, basal cell cancer and squamous cell cancer are the two most common types of skin cancer and those are derived from keratinocytes which are the building blocks of skin. Melanoma is derived from melanocytes which are the pigment producing cells in the skin. And melanoma, it’s different in that it grows and can potentially metastasize much more readily than a basal cell cancer or squamous cancer. It’s – by metastasize, that means that the cancer can spread from a primary spot on your arm to a lymph node in your armpit or from your cheek to your – a lymph node in your neck or a lung or something like that. Squamous cancer is capable of doing that, but it’s a much lower risk and even basal cell, the chance of that spreading anywhere other than locally is very, very low. And the cancer – a basal cell cancer would have to be much larger, grapefruit sized in order for that to occur.
Melanie: Who’s at risk for melanoma? Is there a genetic component to it and then I’d like you to go into identification and the importance of checking our skin and those ABCDEs? So, start with the risk factors.
Dr. Foster: Well I think there are a lot of risk factors for melanoma and some of those are just having very fair skin and red hair and being out in the sun a lot, especially when you are a child. They have done several studies which show that childhood sunburns increase the rate of melanoma. There are even genetic syndromes that can increase the rate of melanoma including DNA repair diseases and in other words, your DNA, it gets broken when you go out in the sun. When the sun’s rays hit your DNA, the genetic material in your cells, those strands of DNA can become broken and they are repaired. And if you have a defect in the repair enzymes, the proteins that do the repairing; this can result in not only a whole variety of skin cancers but also an increased risk of melanoma. If you have lots of moles, that’s also a risk factor. If you have a familial condition, dysplastic nevus syndrome; that can also increase your risk of melanoma. So, all those things are risk factors and I think one thing for people to keep in mind is we want to monitor for this on a frequent basis, at least yearly would be a good idea. And those people that have had a melanoma before; of course, we are going to check them every three months for at least a year, maybe longer if they have had multiple melanomas.
The way we look for melanoma and sort of monitor for that is using the ABCDE pneumonic. A stands for asymmetry. In other words, if we drew a line down the center of a mole and asked does the left side look like the right side. That would be symmetry if both sides looked the same. If they don’t look the same or they have irregular areas in the left side but not the right side; well, that’s an asymmetric mole. That’s something that we would consider for biopsy that has an increased risk of melanoma. Borders is also something that we look at. We want the borders to be smooth and regular. We don’t want a border that looks like the peninsula of Florida as it juts off the rest of North America. And if you have irregular borders; the parts that are growing out are areas that are growing faster where the cells are multiplying and dividing and undergoing mitosis and so I guess, irregular borders or notched borders are sort of an indirect marker of how fast the cells in the mole are growing.
The ABCDE, C stands for color. If there are multiple colors in the mole of interest, that’s something that we look for and by colors, there - you can have white, gray, blue, gunmetal gray, black, brown, various degrees of tan, even red. Some people might ask how can you get red in a mole? Well, some melanomas are amelanotic, that means they are not pigmented, they have no melanin in them and often those are slightly more dangerous than your average melanoma.
So, those things are - ABCD, the D stands for diameter and the diameter that I have been taught is 6 millimeters. If your mole is larger than 56 millimeters, that’s in textbooks as well; but if it does get that big, then that’s something that you want to look at. Now I have seen melanomas that are one millimeter and normal moles that are 5 centimeters and so, I think the diameter of a mole is not the best indicator for abnormality.
E stands for evolving. If a mole is evolving, it’s changing, it’s growing, it was brown previously, but now it’s black and has little areas of blue in it and the edges have changed. And so, an evolving mole is something that’s very important to look at and often patients will note that on an exam. So, I hope that’s been helpful.
Melanie: Well certainly it has. You have explained it so well Dr. Foster. How is melanoma staged and what would be the typical first line of treatment once you have identified it? Because I mean this is a scary type of skin cancer. People hear that word and think it’s a God forbid, so tell us a little bit about first line treatment.
Dr. Foster: Well, I think that how we treat melanoma is really dependent on the stages of melanoma and that’s an evolving issue. We use a T, M, and N system for staging melanoma. And usually, when we look at melanomas, we are looking at the depth, the Breslow thickness of the melanoma, how deep has the melanoma penetrated from the surface of the skin and we are also looking at the mitotic rate, the number of mitoses that are occurring in the melanoma itself and then we are also looking at something called ulceration. And ulceration is sort of like if you – it’s like a tree. If you planted a tree and the tree grew really quickly and it grew so fast that it outstripped the nutrient supply and the water supply, and the tippy top branches of the tree turned brown and died. That’s the same idea as ulceration. With ulceration, you have a spot on your arm, black spot melanoma, it grows really quickly, it makes a big lump, at the top of the lump the tissue is growing so rapidly it outstrips the blood supply and that part necrosis, it just dies and turns to scab. So, ulceration is an indirect measure of growth rate. Mitosis is also a measure of growth rate, a more direct measure.
Now if you think back to junior high school, that was the first time I had ever heard of mitosis, but when the cells divide; the chromosomes line up in the middle of the cell and then it pinches off into two daughter cells, they call them. And these little lined up chromosomes you can see them with a light microscope and so we call those mitotic figures. And a mitotic figure means that that cell is dividing, and, in some melanomas, you can see many mitotic figures, 60 per high power field and most melanomas you don’t see many or maybe just one per high power field. And if you see ulceration or numerous mitotic figures; that can be something that is – it portends a bad diagnosis. I guess the chance of having a metastatic lesion are increased with that. So, that’s bad. Also if a melanoma is very deep, then that is also not good and so, we use those things the depth, the Breslow depth and the ulceration whether it’s present or absent, and the mitotic rate to sort of stage the melanoma. And a T-0 melanoma is probably the most common. This is called melanoma in situ and this stage of melanoma is characterized by all the bad cells being on the top and that’s really just a surgical issue. In other words, the melanoma can be fully removed by just excising it or removing the piece of tissue. Of course, when we take a piece of tissue out we are always going to want to know if the cancer cells are gone and we are going to embed it in wax and stain it and look at the edges and the margins and make sure they are all free. So, that’s for a T-0, a stage zero melanoma in situ.
For T-1a melanomas, those are melanomas that are generally less than .75 millimeters in depth. That’s the Breslow depth. And they have zero mitotic figures and no ulcerations. So, those are slow growing melanomas that have not invaded the deep tissues yet and consequently those are also ones that we excise. We would treat merely by removing the tissue and that would be it.
Anything that has lots of mitoses, ulceration or a Breslow depth of greater than .75 is something that we would send for sentinel lymph node biopsy. That means that there’s an increased chance that the melanoma cells could have spread from the site where it originated in the arm or the leg or wherever, to a lymph node somewhere. And so, sentinel lymph node biopsy can find those and there has been some debate as to whether sentinel lymph node biopsy improves outcome. I think that it does give the doctor a better way to give the patient a prognosis to more firmly delineate the prognosis. But I don’t know that it increases survival and I think the jury is still out on that. There are people that are still running trials to try and figure that out.
So, most melanomas can be – most melanomas are simple, and most can be treated with excision. Those that aren’t, the first line of treatment would be visiting a quality cancer center and having a lymph node biopsy, a sentinel lymph node biopsy the first lymph node that drains that site of skin from where the melanoma was originally identified and then probably a follow up scan of some type or another. A CT scan, a PET scan to try and identify any or rule out any potential metastases into other areas. So, those would probably be the first things that I would do if I had a melanoma. I would see if – is it – what’s the stage, and is the stage advanced enough that I will need more than just a mere excisional treatment of the melanoma and if that was the case; then I’m going to find a good cancer center and I’m going to go there and have a consult and ask a little more information about what else would be recommendable.
Melanie: As we wrap up, Dr. Foster, give your best advice for prevention in the first place. Is putting on sunscreen enough? What would you like the listeners to take away from this episode about melanoma and prevention and identification, just so that it can, if it is there, be caught early and treated?
Dr. Foster: Well, I think the best thing for prevention is early prevention of sunburns and I think when you go to the beach, Clear Water Beach or wherever you are going to go; it’s really pretty and the sun’s out and it’s easy for kids to get a lot of sun. And children with very fair skin who go to the beach and get burned, when they are very young; that is probably the thing that’s the most important in terms of prevention. If you can stop that, you may be able to reduce the skin cancers that are developed by age 75 by tenfold. And I don’t have specific data on that; but that is a hunch an educated hunch. Also, I wouldn’t get any sun on my face or I would try and minimize it either through the use of sunscreen or the use of hats. You can also buy sun protective clothing that has sort of its own protective factor built in which is directly related to the tightness of the weave of the thread. So, those are good ideas and then if you have had skin cancer; you need to keep up with it. You need to go to your dermatologist once a year or if you have had several skin cancers maybe you are on a three-month plan. We have some people that come every two to four weeks for significant problems.
Melanie: Dr. Foster, thank you so much for being on with us today and sharing your expertise and explaining so very well for us about melanoma, how really dangerous it can be and those identifying ABCDEs. Thank you again for clearing that up for us. You’re listening to BayCare HealthChat and for more information please visit www.baycare.org, that’s www.baycare.org. This is Melanie Cole. Thanks so much for listening.
Melanoma Skin Cancer Risk Factors and Prevention
Melanie Cole (Host): Melanoma is the most dangerous form of skin cancer. And here to tell us about it is Dr. K. Wade Foster. He’s a dermatologist, Owner and Medical Director Florida Dermatology and Skin Cancer Center. Dr. Foster, what is melanoma and how is it different from normal skin cancer that people have heard about? Why is it so deadly?
K. Wade Foster, MD, PhD (Guest): Well I think to answer how it is different, basal cell cancer and squamous cell cancer are the two most common types of skin cancer and those are derived from keratinocytes which are the building blocks of skin. Melanoma is derived from melanocytes which are the pigment producing cells in the skin. And melanoma, it’s different in that it grows and can potentially metastasize much more readily than a basal cell cancer or squamous cancer. It’s – by metastasize, that means that the cancer can spread from a primary spot on your arm to a lymph node in your armpit or from your cheek to your – a lymph node in your neck or a lung or something like that. Squamous cancer is capable of doing that, but it’s a much lower risk and even basal cell, the chance of that spreading anywhere other than locally is very, very low. And the cancer – a basal cell cancer would have to be much larger, grapefruit sized in order for that to occur.
Melanie: Who’s at risk for melanoma? Is there a genetic component to it and then I’d like you to go into identification and the importance of checking our skin and those ABCDEs? So, start with the risk factors.
Dr. Foster: Well I think there are a lot of risk factors for melanoma and some of those are just having very fair skin and red hair and being out in the sun a lot, especially when you are a child. They have done several studies which show that childhood sunburns increase the rate of melanoma. There are even genetic syndromes that can increase the rate of melanoma including DNA repair diseases and in other words, your DNA, it gets broken when you go out in the sun. When the sun’s rays hit your DNA, the genetic material in your cells, those strands of DNA can become broken and they are repaired. And if you have a defect in the repair enzymes, the proteins that do the repairing; this can result in not only a whole variety of skin cancers but also an increased risk of melanoma. If you have lots of moles, that’s also a risk factor. If you have a familial condition, dysplastic nevus syndrome; that can also increase your risk of melanoma. So, all those things are risk factors and I think one thing for people to keep in mind is we want to monitor for this on a frequent basis, at least yearly would be a good idea. And those people that have had a melanoma before; of course, we are going to check them every three months for at least a year, maybe longer if they have had multiple melanomas.
The way we look for melanoma and sort of monitor for that is using the ABCDE pneumonic. A stands for asymmetry. In other words, if we drew a line down the center of a mole and asked does the left side look like the right side. That would be symmetry if both sides looked the same. If they don’t look the same or they have irregular areas in the left side but not the right side; well, that’s an asymmetric mole. That’s something that we would consider for biopsy that has an increased risk of melanoma. Borders is also something that we look at. We want the borders to be smooth and regular. We don’t want a border that looks like the peninsula of Florida as it juts off the rest of North America. And if you have irregular borders; the parts that are growing out are areas that are growing faster where the cells are multiplying and dividing and undergoing mitosis and so I guess, irregular borders or notched borders are sort of an indirect marker of how fast the cells in the mole are growing.
The ABCDE, C stands for color. If there are multiple colors in the mole of interest, that’s something that we look for and by colors, there - you can have white, gray, blue, gunmetal gray, black, brown, various degrees of tan, even red. Some people might ask how can you get red in a mole? Well, some melanomas are amelanotic, that means they are not pigmented, they have no melanin in them and often those are slightly more dangerous than your average melanoma.
So, those things are - ABCD, the D stands for diameter and the diameter that I have been taught is 6 millimeters. If your mole is larger than 56 millimeters, that’s in textbooks as well; but if it does get that big, then that’s something that you want to look at. Now I have seen melanomas that are one millimeter and normal moles that are 5 centimeters and so, I think the diameter of a mole is not the best indicator for abnormality.
E stands for evolving. If a mole is evolving, it’s changing, it’s growing, it was brown previously, but now it’s black and has little areas of blue in it and the edges have changed. And so, an evolving mole is something that’s very important to look at and often patients will note that on an exam. So, I hope that’s been helpful.
Melanie: Well certainly it has. You have explained it so well Dr. Foster. How is melanoma staged and what would be the typical first line of treatment once you have identified it? Because I mean this is a scary type of skin cancer. People hear that word and think it’s a God forbid, so tell us a little bit about first line treatment.
Dr. Foster: Well, I think that how we treat melanoma is really dependent on the stages of melanoma and that’s an evolving issue. We use a T, M, and N system for staging melanoma. And usually, when we look at melanomas, we are looking at the depth, the Breslow thickness of the melanoma, how deep has the melanoma penetrated from the surface of the skin and we are also looking at the mitotic rate, the number of mitoses that are occurring in the melanoma itself and then we are also looking at something called ulceration. And ulceration is sort of like if you – it’s like a tree. If you planted a tree and the tree grew really quickly and it grew so fast that it outstripped the nutrient supply and the water supply, and the tippy top branches of the tree turned brown and died. That’s the same idea as ulceration. With ulceration, you have a spot on your arm, black spot melanoma, it grows really quickly, it makes a big lump, at the top of the lump the tissue is growing so rapidly it outstrips the blood supply and that part necrosis, it just dies and turns to scab. So, ulceration is an indirect measure of growth rate. Mitosis is also a measure of growth rate, a more direct measure.
Now if you think back to junior high school, that was the first time I had ever heard of mitosis, but when the cells divide; the chromosomes line up in the middle of the cell and then it pinches off into two daughter cells, they call them. And these little lined up chromosomes you can see them with a light microscope and so we call those mitotic figures. And a mitotic figure means that that cell is dividing, and, in some melanomas, you can see many mitotic figures, 60 per high power field and most melanomas you don’t see many or maybe just one per high power field. And if you see ulceration or numerous mitotic figures; that can be something that is – it portends a bad diagnosis. I guess the chance of having a metastatic lesion are increased with that. So, that’s bad. Also if a melanoma is very deep, then that is also not good and so, we use those things the depth, the Breslow depth and the ulceration whether it’s present or absent, and the mitotic rate to sort of stage the melanoma. And a T-0 melanoma is probably the most common. This is called melanoma in situ and this stage of melanoma is characterized by all the bad cells being on the top and that’s really just a surgical issue. In other words, the melanoma can be fully removed by just excising it or removing the piece of tissue. Of course, when we take a piece of tissue out we are always going to want to know if the cancer cells are gone and we are going to embed it in wax and stain it and look at the edges and the margins and make sure they are all free. So, that’s for a T-0, a stage zero melanoma in situ.
For T-1a melanomas, those are melanomas that are generally less than .75 millimeters in depth. That’s the Breslow depth. And they have zero mitotic figures and no ulcerations. So, those are slow growing melanomas that have not invaded the deep tissues yet and consequently those are also ones that we excise. We would treat merely by removing the tissue and that would be it.
Anything that has lots of mitoses, ulceration or a Breslow depth of greater than .75 is something that we would send for sentinel lymph node biopsy. That means that there’s an increased chance that the melanoma cells could have spread from the site where it originated in the arm or the leg or wherever, to a lymph node somewhere. And so, sentinel lymph node biopsy can find those and there has been some debate as to whether sentinel lymph node biopsy improves outcome. I think that it does give the doctor a better way to give the patient a prognosis to more firmly delineate the prognosis. But I don’t know that it increases survival and I think the jury is still out on that. There are people that are still running trials to try and figure that out.
So, most melanomas can be – most melanomas are simple, and most can be treated with excision. Those that aren’t, the first line of treatment would be visiting a quality cancer center and having a lymph node biopsy, a sentinel lymph node biopsy the first lymph node that drains that site of skin from where the melanoma was originally identified and then probably a follow up scan of some type or another. A CT scan, a PET scan to try and identify any or rule out any potential metastases into other areas. So, those would probably be the first things that I would do if I had a melanoma. I would see if – is it – what’s the stage, and is the stage advanced enough that I will need more than just a mere excisional treatment of the melanoma and if that was the case; then I’m going to find a good cancer center and I’m going to go there and have a consult and ask a little more information about what else would be recommendable.
Melanie: As we wrap up, Dr. Foster, give your best advice for prevention in the first place. Is putting on sunscreen enough? What would you like the listeners to take away from this episode about melanoma and prevention and identification, just so that it can, if it is there, be caught early and treated?
Dr. Foster: Well, I think the best thing for prevention is early prevention of sunburns and I think when you go to the beach, Clear Water Beach or wherever you are going to go; it’s really pretty and the sun’s out and it’s easy for kids to get a lot of sun. And children with very fair skin who go to the beach and get burned, when they are very young; that is probably the thing that’s the most important in terms of prevention. If you can stop that, you may be able to reduce the skin cancers that are developed by age 75 by tenfold. And I don’t have specific data on that; but that is a hunch an educated hunch. Also, I wouldn’t get any sun on my face or I would try and minimize it either through the use of sunscreen or the use of hats. You can also buy sun protective clothing that has sort of its own protective factor built in which is directly related to the tightness of the weave of the thread. So, those are good ideas and then if you have had skin cancer; you need to keep up with it. You need to go to your dermatologist once a year or if you have had several skin cancers maybe you are on a three-month plan. We have some people that come every two to four weeks for significant problems.
Melanie: Dr. Foster, thank you so much for being on with us today and sharing your expertise and explaining so very well for us about melanoma, how really dangerous it can be and those identifying ABCDEs. Thank you again for clearing that up for us. You’re listening to BayCare HealthChat and for more information please visit www.baycare.org, that’s www.baycare.org. This is Melanie Cole. Thanks so much for listening.