More parents of teen girls not fully vaccinated against human papillomavirus (HPV) are intending to forgo the shots altogether - a trend driven by vaccine safety concerns, new research suggests.

That's despite multiple studies showing the vaccine isn't tied to any serious side effects but does protect against the virus that causes cervical cancer and other cancers as well, researchers said.

"There were a lot of very sensationalized anecdotal reports of (girls) having bad reactions to the vaccine," said pediatrician and vaccine researcher Dr. Amanda Dempsey from the University of Colorado Denver.

"Safety concerns have always risen to the top of the pile, in terms of being one of the main reasons people don't get vaccinated, which is unfortunate because this is one of the most well-studied vaccines in terms of safety and is extremely safe," Dempsey, who wasn't involved in the new research, told Reuters Health.

The U.S. Centers for Disease Control and Prevention recommends that all kids - both boys and girls - receive three HPV shots as preteens.

Researchers led by Dr. Paul Darden from the University of Oklahoma Health Sciences Center in Oklahoma City got their data from a national immunization survey that involved phone calls to almost 100,000 parents.

They found that from 2008 to 2010, the percentage of teens who were up to date on their Tdap (tetanus, diphtheria and pertussis), MCV4 (meningococcal) and HPV vaccines all increased slightly.

Still, about three-quarters of girls ages 13 to 17 were not up to date on their HPV series in 2010. And the proportion of parents of those girls who said they didn't plan to get their daughters the rest - or any - of their HPV shots rose from 40 percent to 44 percent, the research team wrote Monday in Pediatrics.

At the same time, the proportion who cited safety concerns as their reason for abstaining from getting the HPV vaccine increased from less than five percent to 16 percent.

For all three vaccines asked about in the survey, other reasons parents gave for skipping their teenagers' shots included not thinking they were necessary, not having had a specific vaccine recommended by a doctor and, for the HPV vaccine, believing their child was not sexually active.

"These are wonderful vaccines preventing severe diseases," Darden told Reuters Health in an email. "HPV is the first vaccine that will prevent cancer, which is a tremendous health benefit."

Dempsey said past research has suggested that although more girls are being vaccinated against HPV, vaccine rates haven't increased as quickly as for other shots, such as Tdap.

Darden reports having been a consultant for Pfizer, and one of his co-authors is on a safety monitoring board for vaccine studies funded by Merck, which makes Gardasil, one of the HPV vaccines.

Parents shouldn't rely on the media or Internet to learn about vaccines, according to Dempsey, since it's hard to tell what information is legitimate.

"If they have questions or concerns, they should trust their provider to give them accurate information about the vaccine," she said.

 Related:

• Cancer deaths down, but new causes threaten
• HPV vaccine may lower cancer rates
• Teens don't have to have sex to be at risk for HPV

A sexually transmitted infection usually thought of in connection to cervical cancer is also tied to a five times greater risk of cancer of the vocal chords or voice box, a new report suggests.

Combining the results of 55 studies from the past two decades, Chinese researchers found 28 percent of people with laryngeal cancers had cancerous tissue that tested positive for human papillomavirus (HPV).

But that rate varied widely by study, from no throat cancer patients with HPV to 79 percent with the infection.

"We're finding that HPV appears to be linked to a number of squamous cell carcinomas of the head, neck and throat," said Dr. William Mendenhall, a radiation oncologist from the University of Florida in Gainesville who didn't participate in the analysis.

However, he told Reuters Health, "I think the risk of HPV on laryngeal cancer is probably relatively low. Most of the patients we see currently that come in with laryngeal cancer have a strong history of cigarette smoking, also heavy drinking."

Along with tobacco and alcohol, having a poor diet and exposure to certain chemicals can increase a person's risk of laryngeal and other head and neck cancers.

The American Cancer Society estimates 12,360 people will be diagnosed with laryngeal cancer in the United States in 2012 and that there will be 3,650 deaths from the disease.

Along with their larger review, researchers led by Dr. Xiangwei Li, from the Chinese Academy of Medical Sciences and Peking University Medical College in Beijing, analyzed 12 studies that compared cancerous and non-cancerous tissues from a total of 638 patients. They found the cancerous throat tissue had 5.4 times the odds of testing positive for HPV infection, compared to non-cancerous tissue.

The analysis was published last week in the Journal of Infectious Diseases.

Mendenhall said that of all head and neck cancers, HPV seems to play the biggest role not in laryngeal cancer, but in cancer of the tonsils and back of the tongue.

However, he added, "the exposure is probably decades earlier. Someone who develops a base of tongue cancer when they're 50, they probably were exposed to the virus years before, in their teens or 20s."

At least half of sexually active people get HPV at some point in their lives, according to the Centers for Disease Control and Prevention (CDC), but the virus is usually cleared by the immune system. Only some of the 40-plus HPV strains have been tied to cancer.

Based on the current findings, it's difficult to know how many of the laryngeal cancers in the original studies were actually caused by the virus, researchers said.

But Mendenhall said extending HPV vaccination to boys and young men, as the CDC has recommended, "will hopefully reduce at least some of these HPV-related cancers."

Most women can wait three to five years between Pap tests to screen for cervical cancer, according to guidelines released by the American College of Obstetricians and Gynecologists (ACOG).

The latest recommendation, which appeared in Obstetrics and Gynecology and is in line with earlier sets of recommendations, marks a further shift away from annual Pap testing, which was once the standard advice.

Now ACOG and the other groups say most women aged 21 to 29 should have a Pap test no more than every three years.

For women ages 30 to 65, the best option is to have a Pap test, along with a test for human papillomavirus (HPV), every five years. Otherwise, a Pap test alone every three years is "acceptable."

"Women can feel very comfortable with this," said David Chelmow, who heads obstetrics and gynecology at Virginia Commonwealth University and led the development of the ACOG guidelines. "The bottom line is, this is enough."

Cervical cancer is caused by long-term infection with certain types of HPV, a virus that causes warts, including genital warts. But there are over 100 strains of HPV, only some linked to cervical cancer.

The Pap test is done to look for abnormalities in cervical cells that may or may not become cancer. The HPV test helps refine things by showing whether a woman has a strain linked to cervical cancer.

But women younger than 30 should not have the HPV test, Cherlmow said. That's because women that age commonly carry the virus, but for a relatively short time before the immune system wipes it out. So testing young women would largely catch short-lived HPV infections that would not contribute to cancer later.

All the new guidelines, Chelmow noted, are aimed at giving women and doctors clearer direction on how often to do cervical cancer screening - and avoid over-testing.

There is now a vaccine against HPV, and women who have gotten it may wonder if they need cervical cancer screening.

The answer is yes, Chelmow said. "They should follow the same screening recommendations as everyone else."

The American Cancer Society estimates that about 12,200 U.S. women will be diagnosed with cervical cancer this year, and 4,200 will die from the disease.

Related stories:

Free birth control cuts abortion rate dramatically, study shows

IUDs best for birth control, even for teens, docs say

HPV shots don't make girls promiscuous, study says

Carissa Ray / msnbc.com

The HPV vaccine doesn't encourage girls to have sex, a new study says.

The HPV vaccine does not send teenage girls out seeking sex, contrary to the protests of some parents who worried about immunizing young girls against a sexually transmitted virus, researchers reported Monday.

While several surveys of teen girls suggested they would not feel free to have sex just because they’d been vaccinated against the virus, this is the first one to make sure that girls were not, in fact, more likely to engage in sexual activity after vaccination.

“We wanted to do an objective clinical survey using data,” said Robert Bednarczyk of the Kaiser Permanente Center for Health Research and Emory University in Atlanta, who led the study.

The human papillomavirus, or HPV, is the main cause of cervical cancer, as well as genital warts. It can also cause other cancers, including cancer of the mouth, head and neck, penis and anus. The vaccine protects against the main cancer-causing strains.

“In 2006, the Advisory Committee on Immunization Practices recommended that all US girls aged 11 to 12 receive the human papillomavirus (HPV) vaccine, with catch-up vaccination recommended through age 26, and administration permitted as young as 9 years,” Bednarczyk’s team wrote in their report, published in the journal Pediatrics.

Many parents were dubious about vaccinating such young girls against a sexually transmitted disease. A few, and some religious groups, said the vaccine would even encourage sexual activity.

But HPV is extremely common. The Centers for Disease Control and Prevention estimates that 20 million Americans are currently infected with HPV. Another 6 million people become newly infected each year. For most, the virus clears their system on its own, but at least 50 percent of sexually active men and women are infected at some point in their lives. Some estimates range as high as 80 percent.

“About one-third of 14- to 19-year-olds are positive for at least one HPV strain,” Bednarczyk said. And a study published in August found some girls were infected even if they'd never had sex.

Cervical cancer kills 3,870 women a year in the United States and 300,000 globally. There are two commercial vaccines -- Merck’s Gardasil and its rival, GlaxoSmithKline’s Cervarix. The idea behind starting to vaccinate 11- and 12-year-olds is to allow full immunity to build long before they ever have any kind of sexual contact for the first time.

It is possible that girls might be confused about the protection provided by the vaccine, Bednarczyk said. They might mistakenly believe it protects them against all sexually transmitted diseases, or even against pregnancy. So he sought cold, hard data on what girls actually did after they got vaccinated.

Bednarczyk and colleagues went through the medical records of nearly 1,400 girls who got either the HPV or another immunization such as the meningitis vaccine. They followed them for three years after vaccination.

“We looked for the first occurrence of any testing or diagnoses related to pregnancy or sexually transmitted infections or any counseling on contraceptive use,” Bednarczyk said in a telephone interview.

“We got up to age 16 which, in some surveys, is where you start seeing more sexual activity among adolescents.”

There were no differences between girls who got HPV vaccine and girls who got other vaccines but not HPV, the team found. “Overall, what we found through the whole follow-up study was among 1,400 girls only eight actual cases of either pregnancy or sexually transmitted infection,” Bednarczyk said.

The rates were identical in the HPV vaccine and non-HPV-vaccine groups. “We feel this is reassuring,” he said. “We can start to move beyond these concerns.”

Rates of sexual activity are going down among school-aged children. The CDC says while 39 percent of all 15- to 17-year-olds had had sex in 1995, the rate fell to 27 percent by 2010. But around 3 percent of girls report they started having sex before the age of 13.

Related stories:

• Large study finds HPV vaccine safe
• HPV vaccine benefits even women who don't get the shots
• Poll: Parental consent should be required for HPV vaccine

Oral sex fuels rise in cancer

Teens risk HPV even if they don't have sex

Rachael Rettner
MyHealthNewsDaily

The human papillomavirus (HPV) vaccine is generally safe, but may increase the risk of fainting and skin infections shortly after vaccination, a new study finds.

The study included nearly 200,000 girls who received at least one dose of the quadrivalent HPV vaccine, known as Gardasil, which is marketed by Merck & Co. and protects against four strains of HPV.

Researchers found that fainting was six times more likely to occur on the day of vaccination, compared with a period many months after vaccination — there were 24 cases of fainting per 1,000 people on the day of vaccination, compared with an average of four cases per 1,000 people during a time period months after vaccination. 

And skin infections were nearly twice as likely to occur within two weeks of vaccination compared with many months after vaccination. There were 3.5 cases of skin infections per 1,000 people during the two weeks after vaccination, compared with 2.2 cases per 1,000 people during the comparison time period, the researchers said.

Because these side effects were somewhat expected, and the study did not find any new safety concerns, the findings "support the general safety of routine vaccination," the researchers said.

HPV viruses are sexually transmitted viruses that usually cause no symptoms, but persistent infections can lead to cervical cancer. Gardasil was approved in 2006, after studies showed it was safe for use in females ages 9 to 26. But because studies conducted before a vaccine's approval are usually too small to detect rare side effects, researchers have continued to monitor the safety of the HPV vaccine.

In the new study, Nicola Klein, of Kaiser Permanente Vaccine Study Center in Oakland, Calif., and colleagues analyzed information from about 189,600 girls and young women, who received a total of 350,000 doses of the HPV vaccine between 2006 and 2008. The researchers calculated the annual rate of each side effect they observed.

The researchers determined how likely participants were to be hospitalized or visit the emergency room for certain conditions in the 60 days after the vaccination, compared with a period many months after vaccination.

Injections in general are known to be linked with fainting, and so this result "is not unexpected," the researchers said.

There is evidence to suggest some of the skin infections seen in the study were actually reactions at the injection site, but the researchers did not have enough information to confirm this.

Unlike some earlier studies, the new study did not find an increased risk of blood clots linked with the vaccine. The researchers made sure to rule out side effects that were due to conditions the patients already had.

Ongoing studies of HPV are still needed to examine the risk of side effects, the researchers said. They noted that future studies should attempt to rule out effects that could be caused by pre-existing conditions.

The study was funded by Merck, and is published Oct. 1 in the journal Archives of Pediatrics & Adolescent Medicine.

More in Vitals

• The real reason teens do stupid things
• Teen pot use linked to decline in IQ
• More kids get nonmedical exemptions from vaccines

By Rachael Rettner
MyHealthNewsDaily

The human papillomavirus vaccine provides a benefit to women even if they are not vaccinated, via a phenomenon known as herd immunity, a new study suggests.

Among the women in the study, there was a decrease in the percentage who were infected with the four HPV strains included in the vaccine (HPV 6, 11, 16, and 18) in the years after the vaccine was introduced, compared with earlier years.

This decrease in HPV prevalence was seen among both vaccinated and unvaccinated women, the researchers said.

The findings show that even with relatively low rates of women getting vaccinated, the vaccine produces some degree of herd immunity — protection of unvaccinated people that occurs because a critical portion of the population has been innoculated.

However, while the findings are encouraging, "This is not reason not to get vaccinated," said study researcher Dr. Jessica Kahn, a physician of adolescent medicine at Cincinnati Children's Hospital. Kahn noted that one in four unvaccinated participants in the study were infected with a high-risk strain of HPV. A woman can also protect her partner by getting vaccinated, Kahn said.

Because the study was conducted in just one community of mainly African American women, further research is needed to confirm the results and see if the findings apply to the population as a whole.

Herd immunity
The first HPV vaccine, called Gardasil and manufactured by Merck, was licensed for use in the United States in June 2006.

To study the effect of the vaccine, Kahn and colleagues analyzed information from two groups of sexually active women ages 13 to 26. One group consisted of 368 women who were not vaccinated, and who visited clinics in Cincinnati between 2006 and 2007. The second group consisted of 409 women who visited the clinics between 2009 and 2010, about 60 percent of whom had received at least one of the three shots in the HPV-vaccination series.

Overall, the percentage of women infected with one of the HPV strains included in the vaccine decreased from 31 percent in the group that visited the clinics between 2006 and 2007, to 13.4 percent in the group that visited in 2009 and 2010 — a 58 percent decrease.

Among women in the latter group, 9.9 percent of those who were vaccinated tested positive for HPV, while 15.4 percent of the unvaccinated women were infected.

The percentage of women infected with HPV strains not included in the vaccine increased after the vaccine's introduction, from about 60 percent to 75 percent, but the researchers said this finding should be interpreted with caution, because there is no biological reason this would happen so quickly.

Good news
The study is "good news that comes surprisingly soon," said Dr. William Schaffner, chairman of the department of preventive medicine at Vanderbilt University. Schaffner said he would have expected a larger portion of the population needed to be vaccinated, including boys, to see herd immunity.

"It's impressive if other studies can confirm it," Schaffner said.

 The study is a reminder that "vaccination is not just about the individuals getting vaccinated…it's about everyone else in the community," Schaffner said.

Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia, said he would expect to see herd immunity against the strains in the vaccine starting at a vaccination rate of 40 percent, which is the national average.

The vaccine's effectiveness in reducing HPV prevalence is expected to translate into a decrease in cervical cancer in the community, Kahn said. (HPV is known to cause most cases of cervical cancer ).

Because of the high prevalence of HPV strains, the findings underscore the importance of vaccinating children before they become sexually active, when they are 11 or 12 years old. And the study shows that older women, who are recommended for "catch up" vaccination, also derive a benefit, Kahn said.

The study is published in the July 9 issue of the journal Pediatrics.

• 5 Dangerous Vaccination Myths
• 10 Medical Myths that Just Won't Go Away
• 1 in 4 Couples Share HPV Strains

More from Vitals:

For healthier kids, get a dog or cat, study suggests

After hormone therapy trial: Confusion, mistakes and fear

Why we get cranky when it's hot out

More from Vitals: 

• Trial herpes vaccine misses mark for protection in young women
• FDA cracks down on DIY sperm donor in Calif.
• The scent of a man? It could be an STD

Most women can go as long as five years between cervical cancer screenings as long as they make sure to get both a Pap smear and an HPV test when they do get examined, a government panel said Wednesday.

The interval between cervical cancer screenings can safely be extended for women between the ages of 30 and 65, according to the new recommendations from the U.S. Preventive Services Task Force.
 
Women ages 21 to 30 should still get a Pap smear every three years, the interval currently recommended. But those younger than 21 and older than 65 can skip the screen altogether, the experts concluded.

The panel is urging a extended intervals in screenings in an attempt to cut back on the number of women who end up being treated for lesions that might resolve on their own.

The downside could be a very small potential increase in the number of women who might die of cervical cancer, experts said.

“It’s a trade-off,” said Dr. Michael LeFevre, co-vice chair of the task force and a professor of family and community medicine at the University of Missouri at Columbia.

While screening more often might turn up more cancers and pre-cancerous lesions, it would also lead to far more unpleasant and painful therapies for women who might ultimately not have needed them, LeFevre said.

When a lesion is found, generally a colposcopy is ordered, said Dr. Alan Waxman, a professor of obstetrics and gynecology at the University of New Mexico.

And the often painful test can amount to a lot of unnecessary suffering given that many lesions frequently disappear on their own. For women who’ve never experienced a colposcopy, Waxman offered this description: “It’s like a Pap test on steroids.”

Beyond this, lesions may end up being excised in an uncomfortable procedure that can impact future fertility, the task force found. Studies have shown that some treatments for precancerous lesions can result in adverse pregnancy outcomes, including pre-term delivery, an infant that is underweight at birth, or even stillbirth or death shortly after delivery.

Until experts can find a way to cut back on colposcopies and excisions for precancerous lesions, it makes sense to screen less often because this will give some lesions time to resolve on their own, Waxman said.

He predicted that the new recommendations will take time to be accepted into practice.

“I anticipate there will be some apprehension among ob-gyns about it,” Waxman said. “It’s something new. And there’s always a concern if you screen less often you’re going to miss disease.”

Dr. Thomas Randall is one of those who isn’t yet convinced that the proposed changes are the best solution.  

One thing missing from the new recommendations are studies that look at how women feel about treatment issues, said Randall, director of gynecologic oncology at Pennsylvania Hospital.

“I applaud the panel’s effort to minimize the emotional and physical burden of treatment on patients,” Randall said.  “But I think we need to think very carefully about what patients’ preferences actually are.”

Beyond this, Randall said, it might make more sense to look at ways to decrease the number of colposcopies and excisions rather than cutting back on screening.

“Limiting screening seems a little paternalistic,” he explained. “Maybe we should be looking more at treatment patterns than at screening patterns in order to decrease the burden of treatment.”

The new recommendations were published in the Annals of Internal Medicine.

Related stories:  

Condom use 101: Basic errors are so common

How to be like Beyonce (and breast-feed in public)

By Cari Nierenberg
MyHealthNewsDaily

The nation's largest pediatrician group today released its new schedule of recommended childhood vaccinations. It made three major changes to its previous recommendations, after a federal advisory panel of experts reviewed recent evidence from vaccine studies.

The biggest change is the new recommendation that boys should be vaccinated against human papillomavirus (HPV). Since 2006, the HPV vaccine has been recommended for girls, primarily to help prevent cervical cancer, and in 2009, the experts advised that boys "could" be given the shots, too.

The stronger wording in the new recommendations, that boys "should" be given the shots, came about because new data showed giving boys the vaccine can help lessen the odds of HPV-associated cancers in men and in women, said Dr. H. Cody Meissner, chief of pediatric infectious disease at the Floating Hospital for Children at Tufts Medical Center in Boston.

Meissner was part of the group of experts updating this year's recommendations from the American Academy of Pediatrics; the panel also included experts from the Centers for Disease and Prevention, which had previously recommended the HPV vaccine for boys.

The new vaccination schedules are published today (Feb. 1) in the journal Pediatrics.

Routine HPV vaccinations for boys

The new guidelines call for boys to get the first of the three doses of HPV vaccine at age 11 or 12, the same age the shot is recommended for girls.

HPV vaccinations are also advised for young men ages 13 to 21 if they've not yet had all three shots. It may be given to boys as young as 9 and to men between 22 and 26. 

Young people are encouraged to get all three shots, given over a 6-month period, before they become sexually active.

"Every parent likes to think their child is not sexually active in their early teen years," Meissner said. "But if you wait until they're sexually active, you miss the benefit of the vaccine."

The vaccine has been known to protect against genital warts in males and females, and recent evidence has shown it can prevent anal cancer in men and women. The HPV vaccine has also been shown to be protective against penile cancers, as well as head and neck cancers.

Updates to meningococcal and flu vaccines

The meningococcal and flu vaccines are the focus of the other two changes to the guidelines.

A booster dose of the meningococcal vaccine is now recommended for children at age 16. The previous schedule recommended children be routinely immunized against meningococcal disease, which prevents most types of meningitis, when they are 11 or 12.

Infectious disease experts had thought that one dose of meningococcal vaccine would protect a young person through the college years, Meissner said. "But data became available that the vaccine doesn't last that long, and the risk goes up late in the teen years," he said.

Teens are now advised to get a booster dose to make sure that protection is maintained through the high-risk window, which occurs between 16 and 21 years, when many are living in close quarters, such as in college dormitories.

Some slight tweaks were also made to flu shot recommendations. This was the second year the AAP is recommending that children 6 months and older need to get the annual flu shot, Meissner said.

The new schedule clarifies the guidance for giving the flu shot to kids with egg allergies. Studies have shown the amount of egg protein in the flu vaccine is not enough to produce an allergic reaction in those with mild allergies, who can eat cooked eggs, Meissner said. Still, the flu shot may not be appropriate for people with a severe egg allergy, he said.

Advice for parents

A lot of parents are nervous about the number of shots recommended for children and teenagers these days, and they want to know how long each vaccine has been around, and how serious the risk is if their child does not get it, said Dr. Peter Greenspan, medical director of MassGeneral Hospital for Children in Boston.

He said he has noticed that parents are getting increasingly discerning about immunizations. "I find that parents really want to know the whys about the vaccines, which is entirely appropriate and important information for doctors to share," Greenspan said.

When new changes are made to the vaccination schedule, he said, "it's just a matter of explanation and discussion with your pediatrician."

Pass it on: Experts now recommend that pre-teen boys get vaccinated against HPV, that 16-year-olds be vaccinated against meningitis and that almost all children receive a flu shot annually.

More from MyHealthNewsDaily

5 Dangerous Vaccination Myths

Beyond Vaccines: 5 Things that Might Really Cause Autism

What to Do (And Not to Do) to Ease Kids' Vaccination Pains

By Rachael Rettner
MyHealthNewsDaily

About 7 percent of adults and teens in the United States are orally infected with the human papillomavirus, or HPV, a new study says. This represents about 14.9 million people.

More men are affected than women: About 10 percent of men ages 14 to 69 have an oral HPV infection, compared with 3.6 percent of women, the study showed.

Oral HPV infections cause some oropharyngeal cancers, or cancers of the tongue, the tonsils or back of the mouth. People who are infected with the strain HPV 16 are 14 times more likely to develop these cancers compared with those not infected with the virus.

The new findings were "reassuring," according to study researcher Dr. Maura Gillison, chair of cancer research at The Ohio State University , because they show that while oral infection with the virus is common, cancer cases as a result of these infections are rare. In other words, most infected people don't get cancer. The American Cancer Society estimates there will be about 40,000 new cases of cancer of the oral cavity and pharynx in 2012.

The findings also show oral HPV infections are, for the most part, sexually transmitted. People who reported engaging in oral sex were twice as likely to have an oral HPV infection as those who did not engage in oral sex. People who had had sex of any kind, including vaginal sex or oral sex, were eight times more likely to have an oral HPV infection than those who had not had sex. Among those who'd had 20 or more sexual partners, one in five had an oral HPV infection.

"Taken together, these data indicate that transmission by casual, nonsexual contact is likely to be unusual," the researchers wrote in their study.

However, there are clues HPV may also spread by kissing. Oral HPV infections were more common among sexually experienced people who had not engaged in oral sex than among sexually inexperienced individuals, a finding that is "consistent with transmission by other sexually associated contact (eg, deep kissing)," the researchers wrote in their study.

"This study of oral HPV infection is the critical first step toward developing potential oropharyngeal cancer prevention strategies," Gillison said. "This is clearly important, because HPV-positive oropharyngeal cancer is poised to overtake cervical cancer as the leading type of HPV-caused cancers in the U.S."

More studies are needed to know whether the HPV vaccine effectively prevents oral HPV infections, the researchers said. Currently, the vaccine is recommended to prevent cervical cancer, anal cancer and genital warts.

How common is oral HPV?

Between 1998 and 2004, incidence of new cases of oropharyngeal cancer in the United States more than tripled (from 0.8 cancers per 100,000 people to 2.6 cancers per 100,000 people).

Despite the rise, little was known about the prevalence of oral HPV infection, and the characteristics of those who have it.

In the new study, Gillison and colleagues analyzed data from more than 5,500 men and women in the United States. Participants answered questions about their sexual behavior and substance use. They were also asked to gargle mouthwash for 30 seconds, and cells that were exfoliated into the rinse were analyzed for evidence of HPV infection.

The researchers found HPV in the cells of 6.9 percent of the participants, and HPV 16 in 1 percent.

The infection was most common among those ages 60 to 64 years, (at 11.4 percent), and those ages 30 to 34 (at 7.3 percent).

Physicians should encourage their patients who engage in oral sex to use barrier protection, Dr. Hans P. Schlecht, of the Drexel University College of Medicine, Philadelphia, wrote in an editorial accompanying the study.

Smokers and alcohol users also had a high prevalence of HPV. About 20 percent of those who said they smoke 20 or more cigarettes per day had oral HPV infection.

More research

It's not clear why oral HPV infection was more common among men than women. It could be that HPV is more likely to be transmitted through oral sex on women versus men, the researchers said. Differences in hormone levels between the sexes could also affect the duration of an infection.

Smoking may suppress the immune system, leading to longer infections with the virus, the researchers said.

The researchers noted their findings are based on study participant's reports of their sexual behavior and smoking, which may not be completely accurate.

Researchers need to follow people over time to better understand the effects of age, gender, sexual behavior and smoking on the incidence and duration of oral HPV infections, the researchers said.

The study will be presented this week at the Multidisciplinary Head and Neck Cancer Symposium in Phoenix. The study and editorial are published online today (Jan. 26) in the Journal of the American Medical Association.

Pass it on: Oral HPV infections affect about 7 percent of adults in teen in the United States, and are more common in men than women.

More from MyHealthNewsDaily:

5 Reasons Being a Woman Is Good for Your Health

5 Dangerous Vaccination Myths

Busted! Gender Myths in the Bedroom & Beyond

A huge spike in the number of head and neck cancers linked to HPV over nearly two decades is raising alarms about the risk of the sexually contracted infections in a whole new population: men.

Between 1988 and 2004, head, neck and throat cancers that tested positive for the human papilloma virus rose an astounding 225 percent, according to a new study in the Journal of Clinical Oncology.

Within the next decade, the study authors argue, the incidence of such cancers — which are almost always contracted as a result of oral sex — will surpass that of cervical cancer, and the majority of those cases are going to be in men.

That’s a point often missed in public talk about HPV infection — and the vaccine that can prevent it.

In the recent controversy over comments made by presidential candidate Michele Bachmann about the HPV vaccine, the focus was squarely on young women and cervical cancer. But HPV, mainly a strain called HPV-16, also causes oropharyngeal and anal cancer, a fact not often publicized because medical organizations, the government, and academics would rather not step into any debates about sex practices.

Until recently, head and neck cancers were primarily diagnosed in older people, with an average age of 60, said Dr. Gregory Masters, an expert with the American Society of Clinical Oncology. Those cancers were usually caused by smoking or drinking too much booze, exposures that take 20 years or more to trigger disease. And, they typically didn't test positive for HPV markers. In fact, the incident of HPV-negative head and neck cancers declined by more than 50 percent during the 16-year study period, mostly because of declines in smoking and other tobacco use.

Now, however, oncologists like Masters, who is affiliated with the Helen F. Graham Cancer Center in Newark, Del., are seeing the average age of head and neck cancer diagnoses drop as younger people develop HPV-caused cancers resulting from sexual exposure.

The study authors collected their data from the three states that participate in a government cancer incidence database for oropharyngeal cancer: Hawaii, Iowa and Louisiana. They determined the HPV status of 271 tumors and found that the prevalence of HPV-related cancers increased from 16.3 percent during 1984-1988 to 71.7 percent from 2000 to 2004. 

An accompanying commentary noted that “we can expect some 10,000 to 15,000 patients with (the cancers) per year in the United States, with the great majority having HPV-positive (cancers)."

Consultants to drug companies that make HPV vaccines are represented among the study’s authors; clearly the companies have an incentive to suggest that males be vaccinated. But in many cases, health experts believe that economics and health are aligned on this issue and that boys and young men ought to be receiving the HPV vaccine right now. For instance, Dr. James Turner, a past president of the American College Health Association and a liaison to the Advisory Committee on Immunization practices has long advocated vaccinating all boys against HPV.

Yet neither the Centers for Disease Control and Prevention nor medical organizations such as ASCO have recommended it, although the vaccines are approved for use in males. The reason, suggested Masters, is squeamishness.

“When we get more comfortable as a society with the whole discussion of sexually-related cancer, then you will, I think, see us saying it makes a lot of sense for all boys and girls to get vaccinated … I am not, as a representative of ASCO, saying we recommend it, but I think (such recommendations) are forthcoming.”

Meanwhile, suggested a commentary accompanying the study, “patients should be encouraged to minimize behaviors that put them at risk.”

That, of course, would mean reducing oral and anal sex, two activities now firmly entrenched in the American mainstream. According to the National Survey of Family Growth issued last March by the National Center for Health Statistics, about 90 percent of both men and women have engaged in oral sex with an opposite-sex partner, and 36 percent of women and 44 percent of men have had anal sex.

Statistics like that, and the new study’s findings on head and neck cancer rates may combine to make a broader vaccine recommendation more urgent.  

Follow Brian Alexander on Twitter.

Related:

• HPV shot dilemma: Should gay boys be targeted?
• Guys, man up and get vaccinated: HPV is your responsibility