Alarming Increase in Throat Cancer Due to HPV

MD Anderson Cancer Center
Date: 11-28-2011

 

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Lisa Garvin: Welcome to Cancer Newsline, a podcast series from the University of Texas, M.D. Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research, diagnosis, treatment and prevention, providing the latest information on reducing your family's cancer risk. I'm you host, Lisa Garvin. Today, our guest is Dr. Chris Holsinger. He's Associate Professor of Head and Neck Surgery here at M.D. Anderson and our subject for today is Throat Cancer. And recent news out that there's been a huge increase in the number of throat cancers reported in the US, pretty big job, Dr. Holsinger.

Dr. Chris Holsinger: That's exactly right. Thanks again Lisa for having me back. It's a pleasure to meet with you here online. Yes, so recently, there have been several studies that have shown a dramatic increase in the number of throat cancers in particular in the oropharynx. So there has been a rise of oropharyngeal cancers. One study from the Seer database, which is large epidemiological database that covers 14 states, showed 225 percent increase in this cancer over the last couple of decades.

Lisa Garvin: What is that all about?

Dr. Chris Holsinger: Well, in a phrase HPV, the human papillomavirus. There's good evidence emerging from a variety of centers including our own, and Dr. Erich Sturgis here at the University of Texas, M.D. Anderson Cancer Center has really played a very important rule in helping to unravel this mystery. But it seems that patients who had exposure to the human papillomavirus seemed to be at greater risk for contracting later in life oropharyngeal cancer. Yeah, that's a very interesting new finding and we're sorting out the behaviors that might be associated with that but also the genetics that might predispose someone to getting that disease.

Lisa Garvin: And there are several different strains of HPV. Have you identified particular ones that are risk factor for throat cancers?

Dr. Chris Holsinger: Lisa, great--great questions. Yes, there are a handful of subtypes that of the, let's say, more than 200 that are out there that will place a patient at greater risk. There's primarily subtypes of 16, 18, I think 33 and 35 as well, and these are the exact same subtypes that are placing women at risk for cervical cancer and it's what leads a large public health efforts for pap smears and cervical cancers screening.

Lisa Garvin: And as far as HPV goes, it is a sexually transmitted disease but most people don't even really know that they have HPV, is that correct?

Dr. Chris Holsinger: That's exactly right. And what we're seeing is there's a large latency period if you will between the potential exposure of HPV into the throat and the subsequent developing of oropharyngeal or throat cancer.

Lisa Garvin: Given that HPV is a major risk factor for throat cancers, it sounds like public health issues come into play and when we have a vaccine, Gardasil, that is preventing cervical cancer in women. But it sounds like it might have the same implications for men.

Dr. Chris Holsinger: Right, yeah, exactly. And Lisa, a very important point to bring up. And of course anyone who watched the presidential debates this fall can help but have thought about this issue as well. So that's exactly right. So, there's a tremendous literature out there about the HPV vaccine and it's very successful at preventing cervical cancer. Since those same viruses that cause cervical cancer are effectively prevented with the vaccine, then many of us hope, and although that we don't have scientific proof, but the rest of us who are head and neck oncologists hope that those patients who received the vaccine initially for cervical cancer might be prevented completely from getting head and neck cancer one day. We hope that will be the case. And I think in the last month, the CDC has actually recommended for the first time that boys as well as girls be vaccinated for HPV. And I think, you know, again I'm not an epidemiologists, I'm a head and neck surgeon who deals with this on a patient to patient level but to me, that makes a lot of sense. And I know the, you know, the CDC makes a recommendation and then I think the Secretary of Health and Human Services has to sign off on that but I think that's a step on the right direction because if oral sexual contact is a cause for head and neck cancer, then it seems to me that preventing that in men and women through a vaccine before the age of sexual activity just makes good sense. And so, I know there are a lot of labs and a lot of institutions including our own who are studying that actively, and I'm sure that we'll have a lot more clarity on that issue over the coming years.

Lisa Garvin: Can we put to rest the misinformation that's been floating around about Gardasil? I mean, you know, it's been used as a political football. I mean--

Dr. Chris Holsinger: Right.

Lisa Garvin: It's--

Dr. Chris Holsinger: Right. So I think, you know, again, I'm sort of hedging, you know. So, I'm a surgeon, I'm not an immunologist but to me, you know, the American Academy Of Pediatrics has really shown that in the vast, overwhelming majority of young kids who gets vaccine, these are safe, these are safe medicines for them. And while there are some rare complications from getting the vaccine, whether it's your MMR or your HPV vaccine or your Hepatitis A Vaccine, most of the time, these vaccines are safe and there's good literature to support that. And so, what you have here is a 225 percent increase in the number of head and neck cancers. Maybe upwards and almost 35000 cases now who have oral and pharyngeal cancers. If a vaccine can make this disease go away in my professional life time, I'm gonna be happy to have something else to worry about and other patients to operate on.

Lisa Garvin: Now as far as the oropharynx, let's do a little anatomy lesson here

Dr. Chris Holsinger:Yeah

Lisa Garvin: What part of the throat are we talking about?

Dr. Chris Holsinger: Right, exactly, so for instance, it's--unless you have an endoscope or dental mirror you actually can't see the oropharynx. When you are--even with a flash light at home and a mirror, you couldn't actually see much more than say the start of the tonsils. But for instance, everyone knows what the tonsils are. The tonsils are actually part of the oropharynx. They're kind of the front ward, most facing part of the oropharynx but then also as you go down, pass the tonsils into the base of the tongue, these are the predominant two areas that we're talking about. So the way I described it to patients is, it's not in the oral cavity 'cause you can see that. But it's not in the deeper aspects of the throat where the voice box lies. It's really that area in between. It's that transition zone.

Lisa Garvin: So we're talking about maybe a couple of inches over all?

Dr. Chris Holsinger: Exactly. Yeah, 1 or 2 inches and it's that--it's right where you begin to kind of--it's that transition zone of swallowing where you go from chewing food in the mouth to begin to swallow.

Lisa Garvin: Now, in this increased number of incidences, is it evenly distributed between men and women and or certain age groups or ethnicities?

Dr. Chris Holsinger: Great, great question. We're just starting to unravel all of those factors. In a lot of literature that's published, it seems that men are slightly at greater risk than women. This appears to be, that affects heterosexual and homosexual populations probably the same. It may have a varying incidence based on ethnicity, although those studies I think are inconclusive at this time. And it's tending to hit much younger patients, you know 'cause we've talked about larynx cancer before on Cancer line, that smoking in past, smoking and also drinking are really those historical reasons for why patients use to get throat cancer both in the larynx and then the oropharynx. And now, we're saying HPV emerging as a cause for patients with much--at much younger age presenting with oropharyngeal cancer.

Lisa Garvin: So, basically, the HPV transmission if you will is through oral sex?

Dr. Chris Holsinger: The route through which this disease may be spread is through oral sexual contact. A couple of studies over the last say 5 years, have shown the increasing numbers of oral sex partners seem to correlate with an increase risk of oropharyngeal cancer. Now, that's a very complicated disease process though, right? So, you know, patients who have simply had oral sex in the past are not at a 100 percent risk for developing oropharyngeal cancer, let's--let's just get that out there. But what's frustrating now is that we have identified this as a risk factor but there are so many other factors, genetics, perhaps AIDS, perhaps gender, et cetera, that there's clearly an interplay between genes and exposure, between oral sex history and genetics that probably lead a patient to many years down the road, perhaps with a latency period of as long as 30 years or more to develop oral sex--to develop oropharyngeal cancer I should say.

Lisa Garvin: Now when we're talking about genetics, I know that we've talked a lot about DNA repair and some people just have better DNA repair genes than other people.

Dr. Chris Holsinger: Right. So I'm the head and neck surgeon and I am doing some work in the laboratory but I certainly am not an expert in the molecular biology and the genetics of this disease. But as a clinician, who is in the clinic, talking to patients, scratching their heads, wondering how they got this. This is a working theory I think a lot of us have who are faced with a patient in their family, because they are asking us, "Is my partner at risk?" Can I kiss my children good night?" I mean, there are all these, when you hear about this might be transmitted, it's very alarming. And so, all these questions are coming up. And the best way that I can think of it is that, in this area that we talked about before in the oropharynx where the tonsils and the tongue based are, there's a very unique area of lymphoidal tissue that overlies epithelial tissue. In fact they're blended together almost in very tight layers. And it's in the lymphoidal tissues that you can have a chronic HPV infection, we think. And that over years, that lymphoidal chronic HPV infection might allow this virus to sort of skip over into the epithelial tissues and gain access to a different type of environment, and then from there, over the course of decades, evolve into a tumor. And so, how we unravel the precise cause of all these things is gonna be the source of some very, very active scientific inquiry over the next 5 years, in fact not only scientific inquiry in the lab but also in clinical research. The NIH sponsored a clinical trials planning meeting that we just had this past weekend, where specialist and surgery like myself in radiation oncology, medical oncology, epidemiology, all got together to try to figure out a way to study this in the setting of perspective clinical trials research, and I think it's gonna be a real priority for us here in M.D. Anderson to contribute to that.

Lisa Garvin: Should be talk about other risk factors, HPV aside, what are the other risk factors for throat cancer?

Dr. Chris Holsinger: Absolutely. The predominant risk factor for all types of head and neck cancer and through out cancer is still, I would say smoking. Oral tobacco use of any kind is something that puts the patient at risk. Smoking is probably a little bit worse than oral tobacco, although oral tobacco can also be very dangerous in this setting. The idea that you would have a cigar or a cigarette that you then add heat and that combined the energy of the heat perhaps with some underlying carcinogens, and the fact--might contribute to that increased risk of smoking related cancers. But also genetics must clearly come into play here. Finally, the concurrent use of alcohol with heavy tobacco used history. Oral--oral tobacco like a dip or a snuff in cigarettes and cigars combine together probably put you at the highest risk of having a cancer.

Lisa Garvin: And obviously, throat cancer is a delicate situation because physical function and appearance are--can be so affected by this cancer. But you're using minimally invasive surgery. Talk to us, it's transoral microsurgery, is that what you're doing?

Dr. Chris Holsinger: Exactly. It's a transoral robotic surgery, transoral head and neck surgery that we can now do. And in fact when you asked earlier about the anatomy, it reminded me about how difficult it is to treat this area because, if you just think about every breath you take or every bite of food or even a sip of afternoon coffee that you might be having right now while you're listening to this, for you to swallow that safely and taste it and enjoy it is such an incredibly complex process that involves the front part of your mouth, that oral cavity and that transition zone where the food or liquid then goes into the back of your mouth and your tongue directs it perfectly over the voice box so that it does go into your lungs and then everything ends up going smoothly into your esophagus. That's incredibly difficult process to, that the body innately and miraculously everyday somehow manages to execute, almost flawlessly. And so you can imagine that if we operate on that, if we radiate or give chemotherapy for tumor that's in any of those areas, we can profoundly impact quality of life. And quality of life in head and neck cancer are so--so linked because you know, the holiday season is coming up and think about what you do every thanks giving or winter holiday. You go over to another family's house and have a meal or you go have--meet someone for coffee and every so much of our social interactions that happens during a meal, that when we--when cancers and the treatments for them somehow interfere with your ability to swallow, it can have a very dire consequence on your social functioning and then your overall happiness. And so we try very hard to find new ways to cure patients of cancer completely and optimize their function long term. And so, I'm very excited about new technology that allows us to operate robotically through the mouth without any kind of external excisions, with no deformity externally and preserve all of the surrounding structures except for where that cancer in a margin around it and get that out. Instead of having to undergo extensive round of chemotherapy and radiation, we can hopefully provide a minimally invasive surgical cure for this disease especially in younger patients.

Lisa Garvin: Now, as far as throat cancers, are you catching them early, middle, late or just all across the spectrum?

Dr. Chris Holsinger: Alright. It varies. And I think it has to so with that anatomy again. If no one can see a tongue based cancer and sometimes you can't feel it and so often times these cancers will present with metastasis to the neck, little lumps or bumps on the neck will show up and saddle symptoms, a little bit of trouble swallowing, a little bit of pain on swallowing, any kind of blood that might be coughed out after a meal. Those are symptoms that should lead a person or a patient to come in to see a head and neck specialist so that we can look back there with special scoops and mirrors that we have so that we can make sure that something isn't developing. Now of course so many of the things that I described are very common. I don't want to alarm the audience. I mean who doesn't have an upper respiratory tract infection and a week later gets some lymph nodes or some lumps and bumps in the neck, and who hasn't had a sore throat of, you know, the flu and cold season is coming. For those viewers--listeners out there, if any of these symptoms that I just described, sore throat, painful swallowing, lumps and bumps on neck, if any of those symptoms last for longer than 2 or 3 weeks, that's when you ought to come in and really have someone who can look in that area and make sure you don't have an oropharyngeal cancer. That's when we can help you.

Lisa Garvin: Good advice. Thank you Dr. Holsinger. If you have questions about anything you've heard today on Cancer Newsline, contact ask at M.D. Anderson at 1-877-MDA-6789 [background music] or online at www.mdanderson.org/ask. Thank you for listening to this episode of Cancer Newsline. Tune in for the next podcast in our series.