Michael Moore, MD, is the Chief of the Division of Head and Neck Surgery in the Department of Otolaryngology at the Indiana University School of Medicine. He specializes in cancer removal and reconstructive surgery and works as part of a multidisciplinary team managing the treatment of patients with head and neck cancer. Dr. Moore has also served as President of the American Head and Neck Society’s (AHNS) Cancer Prevention Service, a member of the American Cancer Society’s Vaccine Roundtable, and as Chairman of the Board of Directors of Head and Neck Cancer Alliance.
ASHA recently met with Dr. Moore to ask about head and neck cancers caused by HPV.
What are head and neck cancers? Are they all caused by HPV?
Head and neck cancer is just a general term to describe any malignant tumors that start anywhere above the collarbone and below the brain. It can be anything from skin cancers to mouth and throat cancers to those affecting the back of the throat or voice box. They also include salivary and thyroid cancer.
The main risk factors for head and neck cancer historically have been tobacco and alcohol use, because they are carcinogens that affect the areas they come in contact with, such as the lining of the mouth and throat. These have been slowly decreasing over the years because education and tobacco taxes mean that smoking is becoming less and less and the result is less and less smoking-related cancers, which is great.
The only area where the incidence of head and neck cancer is increasing is in what we call oropharyngeal cancers. These are usually at the back of the neck and are mainly due to an HPV infection.
Are these cancers in places you can see inside your mouth?
No. These cancers usually occur at the base of the tongue or in the tissue around the tonsils. If you look at the back of your mouth, it’s kind of at the corner where you can’t see. This tissue has little cavities that filter things out as part of your immune system, and these cavities can act as a reservoir. When you get a viral infection, it can hang out at the bottom of these pits, which makes this area more vulnerable to cancers.
Are these cancers caused by the same types of HPV that cause cervical cancer?
Yes. HPV 16 – which is also the cause of most cervical cancers – is the main factor in HPV-related head and neck cancer. About 90% of oropharyngeal cancers are related to this type.
Does this mean the vaccine – which protects against 9 types of HPV, including 16 – will also protect against oropharyngeal cancers?
We think so, and there’s been some research to back it up. We know it protects against high-risk HPV infection, which is great. The challenge in determining how well the vaccine works is that there is a long latency period between infection and oropharyngeal cancer. Maybe even 20 or 30 years.
And we don’t have tests for precancerous lesions like we do for cervical cancer. The vaccine hasn’t been around that long. Most of the people who get oropharyngeal cancer are in their 50s and were probably exposed when they were teenagers or young adults. It will take a few years before we can show that the vaccine works on a large scale.
Would you still recommend the vaccine to most people?
Yes. The protective effect of reducing persistent infection is significant, and I think studies will eventually find that it reduces the risk for head and neck cancers as well. I’m not a population, but I also think that vaccinating more people will have some sort of overall protective effect. If infection rates overall are reduced, this will have benefits for cancer development.
You mentioned that HPV infection can lurk in the throat for years before it becomes cancer, are there any tests that can look for this? How does someone find out they have head and neck cancer?
There are no screening tests yet. There are some new blood tests that look for what is called HPV cell-free DNA. These are not preventive tests. they are used to get more information when planning cancer treatment. It is possible that at some point they will move on to something similar to a PSA test for prostate cancers, but not yet.
Also there are not always symptoms. In other types of head and neck cancer, such as those caused by tobacco, a person may have difficulty swallowing or persistent pain in the throat because the primary tumor is aggressive. But with oropharyngeal cancer caused by HIV, the primary tumor is usually very small. Sometimes it’s so small, I can’t see it when I look down someone’s neck.
The most common symptom for a person with HPV-related throat cancer is a lump in the neck, such as a lump in the neck. This is actually a lymph node metastasis already which means the cancer has already spread. I’m an oncologist, so I see people diagnosed with cancer when their main symptoms other than the lymph node may be a change in their voice, difficulty swallowing, or a sore throat, often just on one side. Sometimes they have pain in their ear that is actually referred pain from their throat and they may cough up blood.
What are the treatments for HPV-related head and neck cancers?
Much depends on the extent of the tumor and where it is located. There are two approaches. One is to start with surgery and remove the primary tumor and possibly some lymph nodes. And then, depending on how early the cancer was found, we might just keep a close eye on it or decide to do radiation and/or chemotherapy to reduce the chance of any tiny cancer growing back. There is also the non-surgical option that simply uses radiation for early disease and chemotherapy for advanced disease.
These are some of the longest conversations I have with my patients because they are so different. With surgery, you may have more side effects such as pain and difficulty swallowing until your throat heals. With higher doses of radiation, you may experience dry mouth or damage to the taste buds. These are the factors that patients must weigh.
What are the survival rates for head and neck cancers?
As long as it does not spread to other parts of the body, survival rates for HPV-related head and neck cancer can be between 80% and 90% or higher. This is much better than the survival rates for head and neck cancers caused by smoking.
Do people with HPV-related cancers usually get their initial HPV infection from oral sex?
Most likely yes. There have been studies showing that increased number of oral sex partners and early sexual debut are risk factors for developing HPV-related oropharyngeal cancer. But I think there’s a lot we still don’t know.
It’s about four to one, men to women in terms of who gets oropharyngeal cancer, but men who have sex with men aren’t necessarily at dramatically increased risk. An increased viral concentration of HPV in vaginal secretions may explain why the heterosexual population may be significantly affected by it. The immune system may also play an underlying role, but we don’t know that yet.
Are most of your patients aware of the link between cancer, HPV and oral sex when they are diagnosed?
They have usually heard of the virus. Most of them have heard it in relation to cervical cancer, but many of them have not heard it in the context of throat cancer.
Do you think the connection to oral sex increases the stigma surrounding these cancers?
With head and neck cancers there is a stigma to begin with because many people believe it is related to tobacco use and patients believe it was their fault for smoking. I think there is also some stigma around the idea of promiscuity because unfortunately we still have a lot of social stigma around sex.
I think people also worry when they talk to their spouse, I try to emphasize that it’s impossible to say where the HPV came from or which partner it came from.
I also try to emphasize to my patients that the vast majority of adults have been exposed to HPV and that throat cancer is now the most common HPV-related cancer in America. It is almost twice as common as cervical cancer now.
Is this due to the vaccine or the widespread pap and HPV testing?
The biggest is that many cases of cervical cancer are caught in the precancerous stage. The vaccine is also good, but there is a little delay before we see that. For head and neck cancer, it’s really a combination of not getting good screening tests, males getting the vaccine less often, and a longer latency period before cancer develops. So even if vaccination is done in the younger groups, there is a group of people in the next 20 or 30 years who will develop these cancers because they have already been infected with HPV.
I think our Holy Grail of reducing these cancers will be finding a screening test that can be widely used.
