Several articles here point to the fact that oral sex is a major vector of HPV transmission:
l.) Human Papilloma Virus Associated with Oral and Oropharyngeal Cancer
2.) HPV Vaccination May Help Prevent Oropharyngeal Cancer
3.) Researchers affiliated with an international study have reported that oral infection with human papilloma virus (HPV) is associated with the development of head and neck cancers. The details of this study appeared in the May 10, 2007 issue of The New England Journal of Medicine.
Human papilloma viruses are probably the sole cause of cancers of the cervix and have been associated with cancers of the vulva, vagina, penis and rectum. Epidemiologic and molecular biology studies have also suggested that HPV infection may be associated with cancers of the head and neck. The relationship between HPV infection and head and neck cancer was reviewed in 1998 by researchers from the University of North Carolina (see related news). They reported that the overall frequency of HPV in benign and precancerous lesions ranged from 18.5% to 35.9%, depending upon the detection methodology. Using PCR, the overall prevalence of HPV in head and neck tumors was 34.5% (416 of 1,205 tumors). Type 16 HPV, which is associated with cervical cancer, was found in 40% of cases positive for HPV. They also reported variability in other sites including 59% positivity for oral cavity cancers, 43% for the pharynx, and 33% for the larynx. The frequency of HPV positivity in oral samples from healthy individuals ranged from 1% to 60%. Furthermore, age (<60 years) and sex (male) were associated with the presence of HPV in the tumor, whereas tobacco and alcohol use were not.
In the study published in 2003, researchers tested 1,670 patients from 9 countries with cancer of the oral cavity or oropharynx and compared the results with 1,732 control individuals (see related news). The researches reported that HPV DNA was detected in 3.9% of oral cavity cancers and 18.3% of cancers of the oropharynx. Patients with cancer of the tonsils were reported to have HPV in 24.7% of cases. They also reported that individuals with antibodies to HPV type 16 were at increased risk of oral cavity and oropharyngeal cancer compared to the control group with the greatest risk for cancers of the oropharynx. Their data suggested that the effects of smoking and HPV infection together were additive and not synergistic. HPV was more frequent in persons with more than one sexual partner and in those who practiced oral sex.
The current study included 100 newly diagnosed patients (86% male) with oropharyngeal cancer and 200 control patients. These authors reported that high life-time number of vaginal-sex partners (26 or more) was associated with a 3 fold risk of developing oropharyngeal cancer. A high life-time number of oral-sex partners was associated with a 3.4 fold risk of developing oropharyngeal cancer. Oropharyngeal cancer was associated with HPV type 16 and 37 other types of HPV. The researchers also detected HPV DNA in tumor specimens of 72% of patients with oropharyngeal cancer. Seropositivity to HPV 16 was highly associated with oropharyngeal cancer in patients with alcohol and tobacco exposure as well as among patients without such exposure. Tobacco and alcohol use increased the risk of oropharyngeal cancer in HPV negative patients. These authors concluded that HPV infection increased the risk of oropharyngeal cancer in alcohol and tobacco users and non-users. These authors also suggest that the more prevalent practice of oral sex may explain the increased incidence of tonsillar and base of the tongue cancers since 1973. These authors suggest that vaccination with Gardisil® should reduce the incidence of oropharyngeal cancers which would provide “the ultimate proof of causality."
These data confirm previous studies with more details about types of HPV involved. The speculation about the benefits of vaccination of both boys and girls to prevent oropharyngeal cancer is of major interest and should prompt debate of this subject.
D’Souza G, Kreimer AR, Viscidi R, et al. Case-control study of human papillomavirus and oropharyngeal cancer. The New England Journal of Medicine. 2007. ;356:1944-1956.
Oral Sex Implicated in Some Throat and Neck Cancers
HPV virus is cause; vaccination may reduce incidence, experts say
By Serena Gordon
MONDAY, Aug. 27 (HealthDay News) -- Human papillomavirus (HPV), which is believed to be responsible for most cervical cancers, may also be at the root of many cancers of the mouth and throat, new research suggests.
Although the rate of most head and neck cancers has been declining over the past 30 years because more people have stopped smoking, the rate of certain cancers in the throat and mouth hasn't dropped, according to research published in the Aug. 27 online issue of Cancer.
"Smoking prevalence has dropped dramatically, and, likewise, most head and neck cancers have declined in incidence. Cancers at the base of the tongue and tonsil are increasing or have remained stagnant. We're not seeing the reduction in incidence that we would have expected," said study author Dr. Erich Sturgis, an associate professor of head and neck surgery and epidemiology at the University of Texas M.D. Anderson Cancer Center, in Houston.
The study authors suspect the reason may be orally transmitted HPV infections.
"Just as cervical cancer is the outcome of a sexually transmitted disease, as are most anal and penile cancers, people need to be aware that they can get throat or tongue cancer as the consequence of a sexually transmitted disease," said Sturgis. "Oral sex can't be considered safe sex."
Head and neck cancers aren't common; they account for about 3 percent of all cancer cases in the United States, according to the study. Each year, there are about 45,000 new cases of head and neck cancers. Cigarette smoking and excessive alcohol consumption have long been considered the most significant risk factors in the development of these cancers, said Sturgis. Between 80 percent and 90 percent of head and neck cancers can be attributed to tobacco or alcohol use.
In 2005, about 21 percent of Americans were smokers, down from 42.5 percent in 1965. The decline in smoking prevalence began in the 1970s, and about 10 to 15 years later, the incidence rates of most head and neck cancers began to decline, according to the study.
But the rate of some of these cancers didn't go down as quickly as others, and, in the case of cancers of the tongue, the rate has gone up. In 1995, there were fewer than 6,000 cases of tongue cancer. By 2005, that number was more than 8,000, according to the study.
Previous research has found that up to 50 percent of nonsmokers with throat and mouth cancers were infected with HPV, according to the study.
How people get infected hasn't been proven, but experts suspect oral sex may be the cause.
If that's the case, then the introduction of the cervical cancer vaccine for girls and women, which covers the common strains of HPV, may also help reduce the incidence of some head and neck cancers.
"We encourage the rapid study of the efficacy and safety of these vaccines in males and, if successful, the recommendation of vaccination in young adult and adolescent males," the study authors wrote.
"This gives us a good explanation of what we're seeing clinically," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "Engaging in oral sex probably is the mode of transmission."
Both Brooks and Sturgis said that quitting smoking and drinking alcohol in moderation are still good ways to prevent head and neck cancers but that cutting down on those two risk factors may not be enough.
"We always thought, to prevent these cancers, all we had to do was get people to stop smoking and drinking excess alcohol, and stop chewing tobacco, and that we'd eliminate most head and neck cancers," said Sturgis. But, he added, future prevention efforts will likely focus on the HPV vaccine and on safe sex practices. For now, he said, women who've had an abnormal Pap smear and their partners probably shouldn't engage in oral sex.
by Farrel Buchinsky, MD:
The authors do indeed say "we cannot rule out transmission through direct mouth-to-mouth contact."
This issue is further addressed in the accompanying editorial by Stina Syrjänen who is from the University of Turku, Turku, Finland.
"In a study that my colleagues and I performed, involving married couples with healthy oral mucosa (sampling at baseline and at months 2, 6, 12, 24, and 36), the results suggested that the oral route is an important means of HPV transmission between partners: one spouse had a 10-fold risk of acquiring persistent oral HPV infection if the other spouse had persistent oral HPV infection. Oral sex was not associated with oral or genital HPV infection in these studies, and oral HPV infection in one spouse was unrelated to genital HPV infection in the other spouse. In our study and in the study by D'Souza and colleagues [that is the one that appeared in the New England Journal of Med on May 10], however, the patients were different: the couples we studied were younger and had no evidence of clinical lesions in the oropharynx, whereas those in the study by D'Souza and colleagues were older patients who had oropharyngeal cancer."
I looked at the quoted paper and paid particular attention to raw numbers and the methodology. (The abstract is at: http://www.ncbi.nlm.nih.gov/pubmed/16112613?dopt=AbstractPlus. I do not know if that will display as a hyperlink. If it does not then just copy and paste it as one line in your browser's address box). Notwithstanding the conclusions of the data I would not change the advice given to patients. Sometimes data is instructive when trying to work out how things happen but not all data can be used to instruct humans what they should or should not do to materialy reduce their risks of bad things happening.
HPV is indeed capable of causing very bad outcomes but paradoxically it is also only a small part of the picture. This is because HPV is so widespread and the overwhelming majority of the people who are ever infected with HPV will clear it.
by Michael Green, MSW, LICSW
Dr. Buchinsky is right. Oral HPV is bad news, and kissing may spread it. Oral HPV is a disease unto itself, however, just like genital HPV. They are different from RRP, however.
How many of you have HPV growing in your mouths? Perhaps a few, but we're talking very low numbers. RRP is a specific KIND of HPV disease that grows only in the larynx, trachea, bronchus and lungs. It does not grow in the mouth.
Epidemiologically, I know of no spouses who ever got RRP. Out of hundreds of case studies that we and others have, less than a handful of people--I think it was 1-2--ever even appeared to have RRP in the same family. (Dr. Buchinsky himself checked this data out, and for that we should thank him profusely.) Other studies bear this out as well.
The virus sheds copiously in the genital tract and elsewhere but, according to Dr. Bettie Steinberg, et all, it hardly sheds at all in the respiratory tract. It also does not behave like a virus that sheds, which would show multiple occurrences in families if it really did shed.
My point is that there is no data of any kind in any branch of medicine suggesting that RRP sheds to an extent where it is a viable vector of contagion to one's spouse or family members. Not through kissing. Not through sex.
Again, we must not confuse oral HPV with RRP. We might wish to be careful of whom we kiss. RRP patients, however, are not natural vectors of contagion.
Certain uninformed members of the media, I fear, may conclude that because apples and oranges are both fruit, they are identical. Because HPV is a virus, they might conclude, RRP patients should also become objects of fear. I believe some informed voice from the medical/research communities need to weigh in on the epidemiological side of things, in order to avert some potentially unpleasant consequences. Data is good, yes. But the data needs to be relevant.
One further item, which many of you have heard me rant about ad nauseum. For reasons that have consistently evaded even a modicum of scientific curiosity, AIDS patients are not susceptible to RRP. Their mouths may indeed have fulminate ORAL HPV disease. Genitals are often even more affected. Still, they do not get RRP in any greater measure than the normals. My point is that most people--even people living with AIDS--could not catch RRP even if they tried.