San Diego Doctor’s Global Health Mission May Change How Skin Cancer Is Treated
Wednesday, October 14, 2009
Skin cancer is the most common form of cancer in the United States with one million cases diagnosed each year. Xeroderma Pigmentosum (XP) is a rare genetic condition that makes skin cancer a very real threat. It is an extremely rare disease which affects one in a million American children. In a remote village in Guatemala 26 cases of XP have been diagnosed. San Diego dermatologist, Dr. Bari Cunningham, organized a team of health workers to travel to Guatemala to help. Their experience was made in to a documentary, Hidden From Light, which tells the story of a group of kids whose DNA could help change how skin cancer is treated.
MAUREEN CAVANAUGH: I'm Maureen Cavanaugh, and you're listening to These Days on KPBS. We're seeing some cloudy weather here in San Diego today, but usually San Diego lives up to its very sunny reputation. And along with other sun-drenched regions of the world, here in San Diego we're familiar with the dangers of too much sun exposure. Many people in our region have routine scans for signs of skin cancer and are diligent about getting any suspicious looking mole or bump removed as soon as possible. But in a remote village in Guatemala, conditions could not be more different. A new documentary, “Hidden From Light,” tells the story of children who have a rare genetic condition that makes even the smallest amount of sun exposure potentially lethal. They develop skin cancers far more serious than typically seen in the United States. The film shows the terrible damage caused by this disease, but it also tells the story of the doctors who came to help. And it explains why research into this genetic disease may well reveal new information about all types of skin cancer. I’d like to welcome my guests, two people who helped make this documentary possible. Dr. Bari Cunningham is a San Diego pediatric dermatologist. Dr. Cunningham, Bari, welcome to the show.
DR. BARI CUNNINGHAM (Pediatric Dermatologist): Thank you so much for the opportunity. It’s great to be here.
BRIAN KNAPPENBERGER (Documentary Filmmaker): Good morning. Thanks for having us.
CAVANAUGH: Let me start with you, Bari. The story of this documentary begins with a girl named Juana and she lives in the Guatemalan village. Tell us how her family began to notice that something was wrong.
DR. CUNNINGHAM: Well, this family’s story is much like many of the families’ story in this village in Guatemala in that very, very early on, children who are affected with this disease differentiate themselves. They start to notice that the babies have what’s called photophobia, which means they start to squint very – at very early age, about a year. They start to squint anytime the mother will take them out of the hut into the sunlight, and they basically are averting their eyes from the sun. And then over time, in the next year or two, they start to develop little, what are called, puntas, which are basically little freckles on the cheeks of the face. And then gradually over time, those little puntas or the freckles on the cheeks of the babies start to develop into raised bumps and ultimately into skin cancers.
CAVANAUGH: What is this disease called?
DR. CUNNINGHAM: So this disease is called xeraderma pigmentosum and we abbreviate it and call it XP for short. And XP is an incredibly rare, fascinating disease. It’s seen all over the world, not just in Guatemala. I actually have patients with it in my own practice in San Diego, so this is by no means a disease exclusive to Guatemala but it is seen in increasing frequency there and an unusual cluster was found there in Guatemala. And basically what the disease is, is an exquisite sensitivity to sunlight so that any amount of sunlight or ultraviolet radiation from the sun that hits the skin of these individuals will inevitably turn into skin cancer. So these children have an absolute inability to tolerate any amount of sunlight on their skin. Normally, when you and I go out in the sun without sunscreen on, even just walking to the parking lot and our car, we basically are accumulating DNA damage. And all of us, the reason we don’t get skin cancer every day is because the body is designed in a beautiful way to go in and repair that DNA damage that’s occurring every day when we’re walking around campus or we’re walking to the grocery store. But children who inherit xeroderma pigmentosum or XP, they have no enzymes in their skin to repair that damage that occurs from the sun. And so every second of time that they’re accumulating sun exposure on their skin, they’re basically accumulating DNA damage and it’s just a matter of time until that DNA damage turns into skin cancer.
CAVANAUGH: Now when you talk about a cluster in this remote Guatemalan village, how many children there are affected by this – how many families are affected?
DR. CUNNINGHAM: Well, we’re not certain that we’ve identified all the families, to be honest with you. There are several hundred people that live in the village, and we are aware of six families who have children affected by XP currently. And there’s anywhere between 10 and 12 children right now with classic xeroderma pigmentosum. What we believe, there may be others that have not come out and are more fearful of western medicine and may not have been identified. But right now we know of six families that are affected. And families there, I might add, are actually quite different. The size of families, obviously, is different there than it is here, so when I say a family there, I may mean 16 people because a husband and a wife in this village may easily have 14, 15 children.
CAVANAUGH: And how rare is that to have all – so many people affected in one very, very small village?
DR. CUNNINGHAM: Incredibly – Really, incredibly rare. We’re not aware of any other village like this one on the planet. So in the United States, xeroderma pigmentosum is seen with the frequency of one in a million. So there’s about 250 individuals in the whole United States who have XP. But in this village of several hundred people, we know of at least 12 people. You can do the math. That’s an extraordinary number of people and it’s seen with a way higher frequency than one would imagine based on the genetics otherwise. So we think what happened was 100 years ago this village was founded by two people, a founder family, essentially, and they, unbeknownst to them—they had no outward signs of it—but they carried the gene for XP. And the gene for XP is what’s called autosomal recessive, meaning in order for you to express the disease, you have to carry both copies of the disease. And so if you have a mother and father who are carriers, they don’t have any outward signs of it and then subsequently if they have children, they have a 25% chance of carrying the disease. So we think that that founder family that founded this remote village 100 years ago carried the gene and, unfortunately, because this village is so incredibly remote and isolated, that it has just be propagated through generation after generation after generation. And so there’s been no dilutional effect of the gene because this village is so remote. So it’s the remoteness of this village that it’s just unfortunately a perfect storm in – so to speak, that it has allowed it to propagate and it hasn’t been able to be eradicated. Normally, other genes would come in and it would get diluted out and if you’re a carrier, well, what are the chances you’re going to meet another carrier of this one-in-a-million disease? But in that village where everybody’s related to everybody, well, it’s a pretty good chance you’re going to meet somebody that might carry it.
CAVANAUGH: Brian Knappenberger, you are the director of “Hidden From Light.” And you went – Most of the movie is shot in the village that we’re talking about. I wonder if you could tell us something about this village.
KNAPPENBERGER: Well, we – Actually, the majority of the film is shot in a town near the village called Barrias, which is about 35 miles south of the Mexican border. The village itself is very, very remote. It’s hard to imagine a more remote place in a lot of ways. It’s a three-hour, very, very bumpy car ride to get there. And for lots of logistical reasons, the doctors couldn’t set up the operating room there so they set up the operating room in Barrias and were forced to kind of put together what they could in order to prepare for the kids. And then we, as a filmmaker, I went with Peggy Tuttle to the village the first night to – and we followed the kids back on the road in the middle of the night because they were sort of weighing – it’s also a very dangerous road. And, you know, with the condit – because of the sensitivity to light, we had to leave very, very early in the morning, three o’clock, and still sort of late enough where we could avoid any kind of danger on the road.
KNAPPENBERGER: So, anyway – So that’s – So we followed them back and so most of the film actually takes place in Barrias in the operating room.
CAVANAUGH: I saw the operating room and I saw the kind of facilities that were available there and – and it was really hard for the doctors to work under those conditions. I’m – I am – I do want to point out, though, that the name of this remote village in Guatemala is not used in this documentary and I’m wondering why.
KNAPPENBERGER: Well, the woman that first discovered this cluster of disease or sort of began the journey of trying to figure out what was going on—she had no idea what this disease was when they first found it—she has a long relationship with them and she wanted to have some protection of the village and not – and not know exactly where it was.
CAVANAUGH: I see. I see.
KNAPPENBERGER: And so they – that’s the reason.
CAVANAUGH: Well, there’s a scene that we have from the documentary, “Hidden From Light,” where Juana, the child that we were talking about in the beginning of this conversation, is traveling for treatment and the doctors express their respect for these suffering children.
(audio of clip from the documentary, “Hidden From Light”)
CAVANAUGH: That’s a clip from the documentary, “Hidden From Light,” which will be screening in San Diego this weekend. And my guests are Dr. Bari Cunningham, who has made the documentary possible. And the “Hidden From Light” director is Brian Knappenberger. And, Bari, you know, that scene from the movie really does express how your reaction was to the kids as you saw them, these kids who were stricken with XP. And I’m wondering if you could elaborate on that just a little bit because the amount of damage that this disease does to one’s physical appearance and the amount of pain these children were in, it was – it is really extraordinary.
DR. CUNNINGHAM: Yeah, it really is truly hard to imagine in your mind this kind of suffering and disfigurement. It really – it’s hard to describe it, and it’s even harder to try to put yourself in that position of an observer. And, you know, I said this before when Brian interviewed me about the kind of human being hat and the doctor hat are kind of two separate hats in my mind, but the human being hat, when I was there, was just, you know, like David said, I almost shut down, like you almost can’t even process it. But then the doctor in me comes out and says, you know what, there has to be something we can do to try to help these children. You know, we can’t cure them, we can’t take their disease away, but we can’t just be aware of this going on here and just close our eyes and put our head in the sand and walk away. We absolutely have to try to do something. But I’ll tell you that, you know, I’ve really wrestled – When I brought the team back and I surrounded myself with the best, most qualified physicians I could find in the whole world, basically, and I’m so indebted to their help and to their expertise. But when we came back, I wrestled and felt a very strong burden on my shoulder that maybe this was the wrong thing to be doing. I really, the night before we operated, I felt like, gosh, you know, I don’t even know these doctors and maybe they’re just too cavalier and maybe they’re overconfident and I felt, you know, like I was straddling, you know, honoring their dignity but also wanting to do as much as I possibly could. But we really feared that we might lose them and they might die on the table, and if that was the case, that would have dire consequences for the rest of the village and the potential for us helping all the other children. So I really felt the weight of the world, and I’m just so grateful for Dr. Fred Mihm from Stanford, he was the anesthesiologist, and Dr. Gary Fudem from University of Wochester, Massachusetts, who was the plastic surgeon. They were incredibly instrumental in really pushing me and giving us the confidence to go forward and help.
CAVANAUGH: Now, you organized this medical team to go down to the village and, of course, that – the town that you actually did the operations – but, Dr. Cunningham, how did you find out about this village?
DR. CUNNINGHAM: Yeah, it’s an interesting story. I – You know, it’s one in a million disease in the United States, and I happen to have a handful of children that I’ve cared for in my practice in San Diego who happen to have xeroderma pigmentosum, which made me all of a sudden an expert because it’s such a rare disease. And so in taking care of these children in San Diego, I was asked to be part of the formation of what’s called the XP Family Support Group, which is basically a small group of really brave, dedicated individuals, most of whom are parents of children of XP – who have XP, and I was asked to be on their advisory board. And so when I was on their advisory board, they then learned of this village and basically just called me and said, Bari, this is a crazy circumstance we just learned about in Guatemala and, being the support group, we want to go and do what we can. Would you be willing to go down to this village and kind of on a scouting mission and be the only physician that we send and come back and report to us and see if there’s anything we can do to help these children.
CAVANAUGH: Well, we have to take a break right now, and when we return we’ll talk more about the new documentary called “Hidden From Light” and about some of the more typical forms of skin cancer seen here in San Diego and what we may learn from the research gathered in Guatemala. You’re listening to These Days on KPBS.
CAVANAUGH: Welcome back. I'm Maureen Cavanaugh, and you're listening to These Days on KPBS. We’re talking about the new documentary “Hidden From Light” being screened in San Diego this weekend. It’s about a group of children in a village in Guatemala who have a genetic susceptibility to skin cancer. And we are also talking about the prevalence of skin cancer here in San Diego, and what doctors are learning about the disease. We’re inviting listeners to join the conversation. If you have a question or comment on what you’ve heard so far about this devastating form of skin cancer called XP, give us a call, or if you have a question about other forms of skin cancer. Our number is 1-888-895-5727. And my guests, once again, are Dr. Bari Cunningham, a San Diego pediatric dermatologist, and Brian Knappenberger. He’s the director of the documentary “Hidden From Light.” Bari, do we know how people develop skin cancer?
DR. CUNNINGHAM: Well, basically, the sun is the culprit. I mean, if we never exposed our skin to the sun, there would be no skin cancer essentially but, obviously, that’s not very practical and we do expose our skin to the sun. But exposure to the sun’s ultraviolet rays are really what causes the cancer. Every day you go out, you’re accumulating DNA damage and your DNA damage is then repaired by the enzymes in your skin. But since skin cancer generally develops in the outermost layer of the skin, in the epidermis, the good news is that skin cancer, unlike internal cancers like pancreatic or breast or colon, when skin cancer develops it’s detectable in its earliest stages if you’re vigilant and you’re watching for changes. So that’s what makes skin cancer potentially very curable in its earliest stages.
CAVANAUGH: And I read, is it true that this is the most common form of cancer in the world?
DR. CUNNINGHAM: It is. Worldwide, it’s the most common form of cancer worldwide.
CAVANAUGH: Isn’t there – Aren’t there forms of skin cancer that are more dangerous than others?
DR. CUNNINGHAM: Absolutely. So there’s three major forms of skin cancer: basal cell carcinoma, squamous cell carcinoma and malignant melanoma. And by and large, the vast majority of skin cancers in the world are basal cell carcinoma, upwards of 80% of skin cancers are basal cell carcinoma. Those are generally lesions that grow, they bleed, they’re locally invasive but they basically don’t kill you; they’re just locally invasive. Squamous cell is an intermediate form of skin cancer, and that does have the potential to spread, to be more serious, to metastasize but generally is also curable by just basically surgical techniques. Melanoma, on the other hand, is the other end of the spectrum. That’s the third and most deadly form of skin cancer. And melanoma is uniformly deadly. It will kill you in all cases if it’s not detected and treated. And melanoma, thankfully, is the least common of the three kinds of skin cancers but the incidence of melanoma over the past 50 years has increased at a rate faster than any other cancer on the planet, so there are a lot of factors that are coming into play that are making melanoma more common and, unfortunately, more deadly than ever.
CAVANAUGH: Does XP fit into any of those three categories that you just talked about?
DR. CUNNINGHAM: Well, unfortunately, XP is the triple whammy. They get basal cell, they get squamous cell and, unfortunately, they get melanoma. They get them in the same, excuse me, frequency. The most common cancers that an XP patient will get would be a basal cell, second would be squamous and then third, melanoma, but they get them all at about 2000 times the rate than a normal individual…
CAVANAUGH: Oh, wow.
DR. CUNNINGHAM: …would get them.
CAVANAUGH: Now, of course, the XP that you were studying and you were dealing with, coming from this remote village in Guatemala, is genetic in origin but you also mentioned the fact that skin cancer is becoming more common just in general. Is that because our exposure to the sun is more common than it used to be?
DR. CUNNINGHAM: Well, there’s a lot of theories about that. I don’t think we have the answer to it.
DR. CUNNINGHAM: Some people believe that the depletion of the ozone is contributing to the fact that the sun may be more damaging.
DR. CUNNINGHAM: There’s also unhealthy tanning practices that are more common than ever. Tanning parolor usage, unfortunately, around the country is at an all-time high. And actually a recent study confirmed that the risk of developing malignant melanoma, which, as I said, is the deadliest form of skin cancer, it increases by 75% when the use of tanning devices or tanning parlors starts before the age of 30, so when you have that 20 year old college student who’s going to the tanning parlor on a regular basis, it’s not just an incidental lifestyle thing. This is something that can have a major, major impact on her life and on her mortality.
CAVANAUGH: Now, Bari, you said you actually treated people who have XP here…
DR. CUNNINGHAM: Yes.
CAVANAUGH: …in this region.
DR. CUNNINGHAM: Yes.
CAVANAUGH: How is it treated when someone lives in a very sunny climate like San Diego? What precautions does someone have to take?
DR. CUNNINGHAM: It’s an absolute devastating disease for a family no matter where on the planet you live, whether it’s in Guatemala or San Diego. If you can just imagine for a moment if your child or your granddaughter is diagnosed with XP, that means point blank that child can never, for their entire lifetime, expose their skin to the sun. So living in San Diego is definitely more challenging than living in Seattle but it can be done and I’ve been amazed at the resourcefulness of the families who have children with XP. You know, I have a friend who has a child with XP and they go water skiing. You know, they take the child water skiing. Now, she’s completely covered. She has a hood over her head, she’s got a wet suit, they’ve got – they go to all these, you know, strides to make sure that she’s safe but it can be done. But it is – it’s a disease that impacts the entire, you know, family and the entire social network of the child because they can just never go out. They’ll never experience that warmth of the sun on their skin.
CAVANAUGH: Brian, I’m wondering, had you ever heard of this form of skin cancer before you started this documentary?
KNAPPENBERGER: No, I had no idea. I had never heard anything like this. In fact, I mean, I think like most people this is a, you know, just the concept was just – seemed shocking that somebody could live their lives entirely in the dark or would have to, that the sun would serve as a – almost like a kind of poison or something on somebody’s skin. And…
CAVANAUGH: How did you get involved in this project, Brian?
KNAPPENBERGER: Well, we had – I found out about this trip that these doctors were going down to Guatemala through a friend of mine and was sort of recommended that I go with them, basically. So it’s – Yeah, a friend of mine had told me. And I found that I…
DR. CUNNINGHAM: It wasn’t under duress, Brian. We didn’t force you.
KNAPPENBERGER: These – No, I immediately could tell Bari was very passionate about this group of people and I just was completely taken with the doctors themselves and everybody involved, and wanted to follow them down there and to see what happened. You know, see what happened and see what they could do.
CAVANAUGH: Now, Bari, I was intrigued with one thing that I heard about while I was preparing for this, and that was the way the people in this village used to deal with this disease before the doctors came. And there was a lot of superstition involved with it, wasn’t there?
DR. CUNNINGHAM: Yeah, unfortunately, there still is a lot of superstition despite Peggy Tuttle, who’s the U.S. missionary worker who discovered the village and still has an ongoing relationship with these villagers. Despite all of her hard work at educating them that this is not something that the mother thought during pregnancy, this is not a result of some witchcraft or some bad thoughts in the mother’s mind or somebody else wishing them bad, that’s what they thought it was before we tried to teach them otherwise. But, unfortunately, we have a lot of challenges in terms of breaking through some of those social and cultural barriers because they still don’t quite get it. We still have, you know, hour-long discussions with translators trying to explain to them that the sun is really the reason for all these tumors and they’ll nod their head and really understand and we’ll think we made a breakthrough and then an hour later you’ll see their baby crawling outside in a diaper in the sun. So, you know, it’s not like it’s all neat and pretty and tidy and we fixed this village and we’re all done and, you know, you know, smack our hands together and say, you know, that was wonderful. There’s still a lot of work to be done and I give a lot of credit to Peggy Tuttle and her workers who are still down there in the trenches every day trying to educate them.
CAVANAUGH: In fact, we have another clip from “Hidden From Light.” It describes Family Support Services. A woman named Michelle is the executive director for the XP Family Support group. And let’s hear that clip right now.
(audio of clip from the documentary “Hidden From Light”)
CAVANAUGH: That’s a clip from the documentary “Hidden From Light.” And so even light from the surgical room can be damaging to someone who has this condition?
DR. CUNNINGHAM: Yes. Light bulbs in the household can be damaging, and you have to be very careful how much light – you know, we’re all green now and we’re trying to be conscious of trying to conserve energy and so many of us are buying those compact fluorescent lights. Well, you don’t want to do that if you have a child with XP because even though the compact fluorescent lights are more environmentally friendly, they actually emit a low level of ultraviolet A, and that little amount that’s emitted from those light bulbs is enough to damage the skin of an XP child.
CAVANAUGH: This is just an overwhelming amount of information about this incredible disease. Is it possible that in studying this extreme form of light sensitivity that can cause skin cancer, that we’re going to learn something about other types of skin cancers?
DR. CUNNINGHAM: Well, that’s to be seen. That’s our hope. And when we decided to go back to the village and operate and take on the risk that we did, one of the conditions was that we had an obligation to bring specimens and samples back to the United States, back to some of the best researchers in the United States who are working on skin cancer, and we did that. And I’m happy to say that there’ve been some leads from the specimens that we brought back. It’s too premature to say if they’re going to lead to, you know, the answer to skin cancer. That would be really unrealistic to be able to claim that at this stage but I do think it’s reasonable to think that, you know, XP is basically the model for all three forms of skin cancer; they get all three kinds. And so there’s an enormous amount of potential information in those children. And, you know, as I said, skin cancer is the most common cancer on the planet. Basal cell carcinoma, you know, occurs – there’s more than a million cases per year just in the United States alone. So even if we just glean something from these children from these specimens, that could help in our treatment or diagnosis or prevention in skin cancer. The potential for helping millions of people is there and I’m hopeful that we can gain, all gain, something from this little village in Guatemala.
CAVANAUGH: You know, Brian, in this documentary, “Hidden From Light,” we spend a certain amount of time within the confines of a surgical facility and it – as I mentioned earlier in our discussion, it’s a little bit of a – not a surgical facility that we might be used to in the United States. Describe it for us, if you can.
KNAPPENBERGER: Well, they – when they got there, you know, we have a couple of scenes in the film when Bari and Fred Mihm actually – the anesthesiologist, arrive at the medical facility and they are, you know, they’re trying to get it – get a read on what, you know, what do we have ahead of us? What do we – How are we going to create a, you know, a safe operating room out of this? And Fred – They basically had an empty room with, you know, a light that was, you know – and a table. So they had to kind of – Everything that they created, they brought in themselves in a couple of these very small planes that they flew in, three or four of these flights. They all had these very restricted weight limits. So I was pretty amazed by that part. They – In a matter of days, they turned, you know, this room into a really first class operating room.
CAVANAUGH: There’s one scene in the film where a doctor, I believe it’s Bari, goes to turn on the faucet to wash her hands and there’s no water coming out of the faucet.
KNAPPENBERGER: Exactly. Yeah, many – There’s a lot of instances like that where they’ve – they were – just at every turn I think there were challenges. And particularly, I think, for Fred Mihm, who’s an anesthesiologist. I think a lot of the danger of the operation or the risk that involved with these operations was the question, could the children survive the anesthesiology, that was the most – the anesthesia, that was the most dangerous part.
CAVANAUGH: I think it’s fair to let people know that in some ways this is a very hard film to watch, Bari, but I’m wondering what it is that you hope that people learn from this film and take away from it.
DR. CUNNINGHAM: Well, I mean, I think, first of all, it is a difficult film to watch but I have to give credit to Brian Knappenberger because I think he straddled that line very carefully and very skillfully. In the film, it’s not at all exploitive, I don’t believe. I think it’s very respectful of the children. I think he edited it and cut it in such a way that he shows just enough to show how serious it is but not in an exploitive, in your face kind of way, and it’s not at all gory. So I give a lot of credit to Brian and I’m just so, so grateful that he was the one who we were able to wrestle into coming and he’s just made a beautiful film, so I would encourage, if you have listeners who are intrigued by this, I would encourage them to come on Friday night to the screening and watch it because it’s really a beautiful film. I think you’ll come away with a feeling of hope and a feeling of optimism and it – he was able to make this a film that’s got a very happy ending but it’s not sugar-coated and sweet, it’s definitely real life.
CAVANAUGH: I have to ask you in closing, what has happened with Juana, the girl that we originally talked about who had these incredibly severe tumors on her face when you first arrived at this village.
DR. CUNNINGHAM: Well, I’m happy to say that she survived the surgery, which that, in and of itself, is an accomplishment. And not only did she survive but she’s now got some semblance of meaning restored to her life. She doesn’t – she no longer smells, she no longer is in constant pain and moaning. She comes to the dinner table. She plays. She likes to draw. And this was a girl who was blind and bedridden and on her deathbed before. So it’s really an incredible success story from her standpoint but there were other children that benefited as well.
CAVANAUGH: And you and the team plan to go back?
DR. CUNNINGHAM: Yes. We’re in the planning stages of a trip this spring and we’re all, you know, chomping at the bit to get back.
CAVANAUGH: I want to thank you both so much for talking with us today. Thank you, Brian.
KNAPPENBERGER: Thank you very much.
CAVANAUGH: And Dr. Bari Cunningham, thank you.
DR. CUNNINGHAM: Thank you.
CAVANAUGH: I want to let everyone know that the pre-release screening of the documentary “Hidden From Light” will take place this Friday at the Children's Museum in downtown San Diego. And that event starts at 7:00 p.m. Stay with us as These Days continues. You’re listening to These Days on KPBS.