Dental Health Check
HPV and ORAL CANCER
Intro: Welcome to Dental Health Check brought to you by Texas A&M University Baylor College of Dentistry. I’m your host, Dr. Linda Niessen. It’s great to have you here with us today. Today’s installment of Dental Health Check will focus on oral cancer specifically related to the human papillomavirus also known as HPV. Before we get into today’s segment, we want to make you aware this is an interactive session and you are free to ask questions. We will dedicate the last portion of segment to answering your questions related to today’s subject.
Welcome OF EXPERT: Joining us today is Dr. John
Wright, Regents Professor and chair
of the Department of Diagnostic Sciences at A&M Baylor College of Dentistry. Welcome John.
JOHN WRIGHT: Thanks, Linda.
LINDA NIESSEN: John, as a dentist and a pathologist tell us what is HPV.
SUPER: JOHN WRIGHT Overview ( SLIDE 1) Viruses are small pieces of either RNA or DNA. HPV or Human Papilloma Virus is a DNA virus that is wrapped in an outer layer of protein.
LINDA NIESSEN How common is HPV infection? What are the different strains of HPV and which ones should we be most concerned about?
JOHN WRIGHT Slide 2. There are over 150 slightly different strains of HPV. It’s important to remember that most of the HPV strains are innocuous and are not associated with cancer. Most of the cancers are caused by HPV 16 or 18, with some caused by 6 and 11 and some in the 30s and 50s.
LINDA NIESSEN Are there certain parts of the mouth where HPV related cancer would show up?
JOHN WRIGHT Slide 3. One of the problems when reading about HPV and oral cancer is that oral cancer as defined by our National Cancer Institute includes cancers of the lips, cancers of the mouth such as tongue and cheeks, and cancers of the throat or oropharynx. And these are all different diseases. We have found that the great majority of HPV related cancers are found in the oropharynx, which includes the base of the tongue. Very few of the cancers of the mouth proper are related to HPV.
LINDA NIESSEN Tell us what we are seeing in terms of oral cancer associated with HPV
JOHN WRIGHT Slide 4. Today there is a dramatic increase in HPV related cancer. 30 years ago, about 15% of all throat cancers were caused by HPV, today that figure is 75-80%, an increase of approximately 250%. A lot of the patients today are younger and 5-6 times more men than women get throat cancer because of the relationship with HPV.
LINDA NIESSEN What accounts for this change?
JOHN WRIGHT We know that HPV is spread sexually. This traditionally has been through intercourse but as orogenital contact has increased, so has the transmission to the oral tissues. Since the greatest threat of sex for the young is pregnancy, many think, correctly, that they can prevent pregnancy by oral sex, and in fact, many teens today do not think of oral sex as sex.
LINDA NIESSEN As a patient, how do I know if I have HPV in my mouth? Is it important that I know if I have HPV in my mouth?
JOHN WRIGHT You won’t know if you have it. We know very little about the early asymptomatic stage. There is technology available to test for HPV. One tests for all the strains of HPV. This test does not really provide you with useful information. There is another test that is specific for HPVs that causes cancer.
LINDA NIESSEN Do you recommend that your patients be tested for this specific HPV that causes oral cancer?
JOHN WRIGHT Currently we are recommending against testing for HPV. These tests only provide information about a specific point in time. If you are negative, it doesn’t mean you will be negative next week. And if you are positive, we know that most people will clear themselves of the virus anyway. If you are positive, we do not know what your risk is of developing cancer and even if we did, there is no treatment today for HPV infections. So we don’t know what the results mean and we wouldn’t change anything we could do about your management.
LINDA NIESSEN So if you are tested and learn that you are HPV +, will the vaccine, Gardisil help you?
JOHN WRIGHT No, at that point, it will not help you. The vaccine is for prevention, not treatment.
LINDA NIESSEN So now, let’s talk about oral lesions. If a patient has a sore in their mouth, what do you recommend?
JOHN WRIGHT Most sores in mouth are due to local trauma and should heal within one-2 weeks. A warning sign of cancer is a sore that does not heal in 10-14 days. So if you have a sore that does not go away in 10-14 days, you need to see your dentist.
LINDA NIESSEN I have a sore that has not healed in 3 weeks. I visit you and you say you need to biopsy it. What does that mean?
JOHN WRIGHT Under local anesthesia, their doctor will cut out a small sample of the tissue and send it to a pathology lab to be viewed under a microscope to determine what is going on at the cellular level to provide a more precise diagnosis.
LINDA NIESSEN Tell more about oral cancer. How common is it? What causes it?
JOHN WRIGHT Again, oral is a little misleading since it includes lip, mouth and throat. The numbers of patients who develop cancer from smoking and drinking is decreasing and the number due to HPV is increasing dramatically. Throat cancer today is seen predominantly in men and is caused by HPV. There is also a well documented increase in oral cancer in those under 40 years of age who have no history of smoking or drinking.
If the cancer is in the throat, it is usually all HPV. If the cancer is in the mouth and not HPV related, we don’t know the cause of this increase. So it is even more important to see your dentist if you have a sore that does not heal.
LINDA NIESSEN Are some of these oral cancers different from others?
JOHN WRIGHT Lower lip cancer is like skin cancer and is usually not life threatening. The majority of oral cancers on the tongue and cheek continue to be due to smoking and drinking. And the majority of throat cancers are due to HPV.
LINDA NIESSEN Can you tell me how these cancers start?
JOHN WRIGHT Cancer doesn’t arise from normal tissue. It starts from abnormal tissue, that we call the “premalignant” or precancerous stage. If the precancerous stage is caused by smoking or drinking, it can produce red, white or persistent sores. Because these are clinically detectable-easy to see, we treat them surgically and remove them. Unfortunately, we currently don’t know what the premalignant stage of lesions in the throat caused by HPV looks like. So, it is critically important when you visit your dentist, your dentist does an annual oral cancer exam to look for any changes in your mouth.
LINDA NIESSEN Can you tell us what happens if you don’t discover or treat these premalignant or precancerous lesions?
JOHN WRIGHT While they don’t all progress to cancer, many of them do. So we have oral cancers caused by HPV and those that are not.
LINDA NIESSEN Tell me about the treatment for these different types of cancer. Are some lesions more serious than others?
JOHN WRIGHT Slide 5-Those that are caused by tobacco and/or alcohol use are treated by combinations of surgery, radiation and chemotherapy. The HPV cancers are treated with only radiation and chemotherapy. Here we note that the cancers by HPV have a significantly better survival than those that are not. In fact many people with throat cancer today can have their cancer treated and be cured.
LINDA NIESSEN If this is increasing, why don’t more people know about it?
JOHN WRIGHT Because it is not a common cancer and there are not enough Michael Douglases to share their story.
LINDA NIESSEN What was it about Michael Douglas’ statement about his oral cancer that shocked people?
JOHN WRIGHT In a very public sense, he made people aware of how HPV is transmitted. This is essentially a sexually transmitted disease and people were a little surprised and or uncomfortable to learn that it can be transmitted by oral sex.
LINDA NIESSEN How are oral health professional trained to discuss this topic with patients? Is this something discussed during regular dental visits or just with patients who exhibit symptoms or have tested positive for HPV?
JOHN WRIGHT As dental professionals, we are responsible for the oral health of our patients and that is not just teeth and gums but their overall health. One of our goals as educators is to provide knowledge in how to talk to their patients about their health issues. Dentists are not embarrassed to talk with patients about their eating habits as they relate to tooth decay. They should certainly not be embarrassed to talk about sexual practices as related to oral cancer.
Every dentist is trained to do an annual oral cancer examination and as part of that, we encourage them to educate their patients about oral cancer and the risk factors. Dentists should ask about patients’ tobacco and alcohol use and HPV is a risk for oral cancer and which is transmitted through sexual practices.
LINDA NIESSEN So what are the questions you would ask to understand if HPV is a risk factor?
JOHN WRIGHT When you are conducting an oral exam, you have the opportunity to explain what the risk factors are for oral cancer, such as tobacco, alcohol and HPV from oral sex. And we have an obligation to educate them that the HPV is sexually transmitted.
LINDA NIESSEN Let’s talk about the vaccines against HPV.
JOHN WRIGHT The first vaccine on the market, Gardasil, was recommended to prevent cervical cancer in women. About 80-85% of all cervical cancers are caused by one of 4 strains of HPV. The vaccine is effective against these 4 strains of HPV, and called a quadrivalent vaccine. It was originally only recommended for little girls.
LINDA NIESSEN Has this recommendation changed?
JOHN WRIGHT Yes, with the dramatic increase in HPV throat cancer, predominately in men, the Centers for Disease Control and Prevention, also known as CDC, now recommends it for boys and girls.
LINDA NIESSEN With this new recommendation, do you expect to see a decrease in HPV throat cancer 30 years from now?
JOHN WRIGHT Yes, I do. The vaccine has been in use long enough now that there are already documenting the prevention of HPV infection. It may take a generation of these HPV-free children to grow up and not develop throat cancer before we can prove the decrease. About 90% of all the HPV throat cancers are caused by HPV-16, and all the current vaccines are effective against this strain.
LINDA NIESSEN John, this has been helpful in understanding the role of HPV in the mouth. We have a number of viewers with us today who may have questions.
LINDA NIESSEN We are now out of time. John, do you have final comments for the audience?
JOHN WRIGHT Yes, I think it is important for the participants today to be aware of several points:
1) that there is a dramatic increase in the incidence of HPV throat cancer.
2) the HPV virus is transmitted sexually.
3) The HPV viral infection is preventable with the vaccine
4) If you have an oral lesion that does not heal in 7-10 days, see your dentist to have it evaluated.
LINDA NIESSEN John, thank you for your excellent advice today and thank you all for participating in this webcast.