Episode Transcript
Announcer: Medical news and research from University Utah physicians and specialists you can use for a happier and healthier life. You're listening to The Scope.
Interviewer: If you're listening to this podcast, it's because you want to learn more about the HPV virus and the cancer that causes it and probably more specifically because you've heard that it's causing more cases of head and neck cancer. We're with Dr. Marcus Monroe. He is a head and neck cancer expert and let's talk about HPV. There is one type of HPV that maybe more people are familiar with, not so much the head/neck aspect. So first of all, what is HPV? Just give us the basics.
Dr. Monroe: Yeah, sure. So HPV stands for Human Papilloma Virus. It's actually a group of well over a hundred different viruses of which, about 40 are known to be transmitted in humans and of these, a few of these subtypes are known to cause cancer in humans. The most well-known association, which has been known for decades, is the link between HPV and cervical cancer. That's the reason why women are recommended to get yearly screening pap smears.
Interviewer: Before we go any further, I think now more than ever, it's important that parents get their children vaccinated for HPV. There seems to be some hesitance and reluctance to do so. But now, it's starting to move in other parts of the body and this is a cancer that's preventable by vaccine.
Dr. Monroe: Yeah, that's a really great point. So the HPV vaccine, there are a number of different vaccines, all the available vaccines actually cover the most common subtypes of HPV that are related to head and neck cancer and that includes the subtype 16 and 18.
The importance of vaccines is becoming increasingly relevant for HPV. For head and neck cancer, the number of new cases are estimated to surpass that of cervical cancer within the next several years. So this is actually a really rapidly rising cancer. However, unlike cervical cancer, we have no effect of screening mechanism. Meaning, for cervical cancer, we pick up many early premalignant lesions through pap smears, that are then we are able to prevent turning into cervical cancer. There is no equivalent early screening for HPV cancers of the head and neck.
Interviewer: And that makes it particularly dangerous.
Dr. Monroe: And that makes it particularly dangerous. So also the population that is at risk is different. So we're seeing the rapid rise in cancers in men of middle aged years, who don't have other traditional risk factors for head and neck cancers. So non-smokers, non-drinkers. And this is the population that many people do not typically associate with getting benefit from the HPV vaccine. So it's important, not only for young girls but also for boys to be vaccinated.
Interviewer: Up into this point, it has been pretty much medical practice that it's just the girls that are getting vaccinated or?
Dr. Monroe: It has until relatively recently. It wasn't FDA approved for boys. However, that has changed and now the vaccine is approved for both boys and girls and so, I think this is in recognition of the other cancers, other than cervical cancer, which are associated with the virus.
Interviewer: So what's the link between HPV and cancers of the head and the neck? It seems like the two are kind of... it's a venereal disease in one case and now, we're up around the head and neck. That's a long way away.
Dr. Monroe: Yeah. So I think it's important to kind of frame this in the history of head and neck cancer and the most common risk factors, traditionally, have been tobacco and alcohol use and those have been the most common causes of cancers of the head and neck for many, many years. We've seen a decrease in the instance of tobacco use in the U.S. and paralleling this, there has been a decrease in a number of cancers of the head and neck except in this one subgroup, cancers of the tonsil and back part of the tongue.
And it was discovered because of this rising incidents for a number of new cancers in this specific area, we kind of took a step back and said, "Well, what's going on here?" and it turned out that these viruses were associated with the cancers. They were present in the cancers and integrated into the genomes of the cancers. And through, kind of, many years of work, we found that same risk factors that predicted cervical cancers also predicted head and neck cancer. Meaning, increasing number of sexual partners and specific sexual practices, particularly oral sex, increase the risk of developing cancers of the tonsil and back part of the tongue that are HPV related<.
So your question of it, the link between HPV, when we typically think of it as a venereal disease, it's really because of probably changing sexual practices but is still a similar link in that it is spread and transmitted sexually.
Interviewer: When physicians and researchers made this connection, was it a little shocking? I mean, I would think that was like, what? What's that cancer doing there?
Dr. Monroe: It was a little shocking and the interesting thing is it has really changed the conversation that many providers who deal with head and neck cancers have in the clinic. I think the important thing for many spouses of patients with head and neck cancer to realize is that this is a virus that is ubiquitous. Meaning that, if you look at exposure rates in studies that have been done in women, over 80% of the population is estimated to be exposed to this virus at one point during their lifetime.
So I think we want to be careful about framing this in the context of a sexually transmitted disease it is, but also realizing that it's an incredibly common infection. It just happens that for a very small percentage and for some reason we don't quite understand, this infection persists and eventually can lead to the development of cancer.
Interviewer: So who is at risk for HPV related head and neck cancer?
Dr. Monroe: Population that we've seen the greatest increase in risk is white men in their 50s. However, this increased risk is actually noted across genders and ethnic groups. Specifically, when you pare down a little bit more into that population, similar risks factors for other sexually transmitted diseases become apparent and behavior, such as increasing number of sexual partners early age at first sexual onset and the practice of oral sex have all been linked to a higher risk at developing oropharyngeal cancer.
Interviewer: What are some of the symptoms, if you have this type of cancer? You said there is really not an effective screening for it. So what am I looking out for then?
Dr. Monroe: In general, symptoms can be related to the local tumor itself or to the development of the spread of the tumor. These tumors, a little bit different than tobacco related tumors, tend to be actually relatively small. However, they can cause some symptoms such as pain when swallowing, pain in the ear and occasionally, bleeding from the mouth. More commonly, however, they first tend to present when they spread to nearby lymph nodes and those are lymph nodes that are typically located in the neck. And so, the vast majority of people actually present with a new lump in the neck.
Interviewer: Okay. So if you discover a new lump in the neck, run, don't walk, to your physician.
Dr. Monroe: I think the important thing to realize is lumps in the neck can be common, so not to be too scared about them. They can be associated just with reactions to virus illnesses. So I think appropriate course of antibiotics or simply observation is appropriate at first. However, for those that lumps that persist past two or three weeks or seem to be increasing in size, those are the ones that are more and more concerned and should be evaluated.
Interviewer: Is there a treatment for HPV head and neck cancer?
Dr. Monroe: Yeah. So as of right now, the treatment for HPV cancer is very similar to the treatment of non HPV cancer and that includes combination of surgery, chemotherapy and radiation. The good news is that the prognosis for HPV cancer is better than that of non HPV cancers and it's just now that we are beginning to see if we can treat these just as effectively but with less toxicity.
So really an active ongoing area of study in this field is looking at de-intensifying some of the treatments that we do. Radiation, surgery or chemotherapy, because this is such an important area of the throat, we use it more commonly than you think, can be associated with quite a bit of toxicity, damage to dentition, difficulty swallowing, both, in the short and long term, requirements for feeding tubes. And so we're really, kind of, looking at maintaining our same level of cure but decreasing the long term toxicities of our treatments.
Interviewer: Is there a what can be done to prevent this type of cancer? We know one answer is, hopefully, parents are getting their children both boys and girls the HPV vaccine.
Dr. Monroe: Yeah. I think the most important thing from an initial standpoint of prevention is the vaccine. While we don't have specific data and trials that look specifically at oropharynx cancer and prevention from vaccines, we do have trials that demonstrate in cervical cancer, the lowering of the risk of spreading the infection and we know it's the same viruses. While it hasn't been proven yet, there is general widespread thought in the field that vaccines will prevent these cancers. So I think that's the first step.
The second step is realizing that vaccines are only one part of this cancer. So traditional risk factors of tobacco and alcohol use are also linked to these cancers and in fact, there seems to be a link between alcohol, tobacco, specifically tobacco, and the HPV virus where they may work synergistically to promote cancers. So we see a number of patients that have both risk factors for tobacco and HPV.
Interviewer: But once you've been diagnosed with head and neck cancer or any HPV caused cancer, it's too late for the vaccine and you need to move on to a treatment?
Dr. Monroe: Yeah. As of right now, we do not have any evidence that vaccination after you've developed another cancer has any benefit. So really, prevention and prevention really before the onset of sexual activity, given that HPV is such a widespread infection, remember the over 80% of the population has been exposed. But once you have the cancer itself, vaccination of the individual patient is really of no benefit.
Now, one thing that is a benefit and from studies that we've done here in Utah, is demonstrating that there is a link between not only the patient, but also increased risk of family members as well as spouses for developing HPV related malignancies. So while the individual patient may not benefit from vaccination, it's an important message that if you do have a family member that other family members may benefit, one, from vaccine if they're of the appropriate age or two from screening for other HPV related malignancies.
Interviewer: Does it pass genetically? Probably not.
Dr. Monroe: It does not. So it seems to be an environmentally acquired infection and risk factor. However, since we do see some linkage within families and family members, there probably is some genetic susceptibility to prolonged infection, realizing that well over 80% of the population comes exposed, but well under that actually acquire a cancer related HPV. There probably is some genetic susceptibility to clearing the virus that we just don't yet understand.
Interviewer: Is there anything I've forgot to ask or anything you feel compelled to say?
Dr. Monroe: I think the most important thing is to vaccinate your children. Remember, the vaccine is important for not only girls but boys in their early years before the onset of sexual activity.
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