A virus spread during oral sex is now the main cause of throat cancer in people under 50, scientists have warned.

They say the human papilloma virus spread during unprotected sex is to blame for a disturbing rise in potentially deadly oral cancers in the last few decades.

Doctors have called for boys to be vaccinated against HPV just like teenage girls to stop the spread of the disease.

HPV: the Human Papilloma Virus is now thought to be the main cause of throat cancer in people under 50, scientists have warned

HPV is best known as the cause of around 70 per cent of cervical cancers. since 2008, girls have been vaccinated against the virus aged 12 and 13 in schools.however, it can also cause warts, verrucas and other cancers.

Cancers of the mouth and oropharynx – the top of the throat – used to be mainly diagnosed in older men who drink or smoke. but increasingly, it is being seen in younger men.

Prof Maura Gillison of Ohio State University in Columbus said the sexually transmitted HPV was a bigger cause of some oral cancers than tobacco.

She said: ‘We don’t know from strict scientific evidence whether the vaccine will protect from oral HPV infections that lead to cancer. Those of us in the field are optimistic it will – the vaccines in every anatomical site looked at so far have been shown to be extraordinarily effective, about 90 per cent effective, at preventing infections.’

‘When one of my patients asks whether or not they sound vaccinate their sons, I say certainly.’

Girls aged 12 and 13 are offered the HPV vaccine on the NHS to protect against cervical cancer – a disease that kills nearly 1,000 women every year in the UK. the jab is given at school in three doses over six months.

Doctors are increasingly concerned that the sexually transmitted virus is behind a rise in cancer.

Worrying: the sexually transmitted HPV was a bigger cause of some oral cancers than tobacco

In Britain the incidence of throat cancer is rising sharply while in the US the incidence of oral cancers linked to HPV have doubled in the last 20 years.

In Sweden in the 1970s around a quarter of tonsil cancers were linked to HPV, but by the mid 2000s the figure was 90 per cent said Prof Gillison.

‘That’s the most compelling data in a population that the increase in tonsular cancer or oropharynx cancer incidence we’re seeing in a number of places worldwide is possible caused by HPV,’ she said.

Someone infected with HPV 16 – the strain linked to oral cancer- has a 14 fold increase in risk for getting oropharynx cancer, she said.

She added: ‘What is most strongly linked to oral HPV infection is the number of sexual partners someone has had in their lifetimes, in particular the number of individuals on whom they have performed oral sex.

‘The higher the number of partners that you’ve had, the greater the odds that you’d have an oral infection.’

Yesterday, researchers told the American Association for the Advancement of Science conference in Washington CD that teenagers consider oral sex to be ‘casual, socially acceptable, inconsequential and significantly less risk to their health than “real” sex.’

Last year a study at Johns Hopkins University found that HPV posed a greater risk in contracting cancer than smoking or alcohol.

Vaccine: Doctors want boys to be given treatment to protect them against the virus

The American study of 300 people showed that those with more than six partners were almost nine times at greater risk of contracting the disease while those who had already experienced a previous oral HPV infection were 32 times more likely to develop cancer.

Most HPV infections have no symptoms and people often do not need treatment.Sara Hiom, Cancer Research UK’s director of health information, said: ‘Cancers in the mouth and throat are on the increase and rates have been rising dramatically in the UK since the mid 1980s, especially in people in their 40s, 50s and 60s.

‘The proportion of these cancers that appear to be related to infection by HPV is also increasing.

‘But while it’s reasonable to assume that HPV vaccination in girls and boys would protect against these cancers, there is as yet no evidence as to whether the current HPV vaccines are effective at preventing them.

‘The trials done to date have looked at cervical cancer or genital warts as endpoints, so we need new studies to show effectiveness against these HPV-related head and neck cancers.

‘Yet most oral cancers diagnosed in people over 50 in the UK are still related to tobacco and alcohol use.’

Last night’s BBC three documentary, presented by actress Jaime Winstone, discusses the newest potential cause of cancer – oral sex.

But before you declare a life of celibacy or start railing against those fun-killing scientists, we want to clarify exactly what we do and don’t know on this topic.

The reality is that there are still many pieces missing from the puzzle.

HPV and oral cancer

Oral cancer (also known as mouth cancer) rarely hits the headlines. People traditionally think of it as a disease that affects smokers and heavy drinkers in later life. but over recent years, as oral cancer rates have been increasing , so too has evidence for a new cause of the disease.

We now know that certain strains of a common virus called human papillomavirus (HPV) can also cause oral cancer, alongside tobacco, alcohol, betel quid and a poor diet.

We normally talk about HPV in the context of cervical cancer, and it is the main cause of this disease. but the virus can infect other areas of our body. Spread by skin-to-skin contact, not just by sex, HPV affects almost everyone at some stage in their life.

But there’s no need for undue alarm. in most of us, our immune system fights it off and it doesn’t do any harm. but on rare occasions, the virus takes hold, leading to a chain of events that ends in cancer of the cervix, penis, anus, vagina or mouth.

We know that around fifteen strains of HPV can cause cervical cancer, and that the most common of these – HPV-16 – can also cause oral cancer. but we don’t know how often HPV infections lead to oral cancer, nor how the virus ends up in the mouth.

Oral cancer on the increase

Oral cancer – which includes cancers of the lip, tongue, gums, tonsils and parts of the throat – has been on the increase for about thirty years. in 2009, we highlighted oral cancer as one of the fastest rising cancers in the UK, now affecting around  5000 people each year.

Rates of a certain type of oral cancer – cancer of the tonsil – seem to have been rising especially rapidly. according to the latest statistics, there are around 1,100 cases of these cancers every year in the UK.

Scientists agree that many of these tonsil cancers are linked with HPV. but they aren’t sure exactly how many are related to the virus, and estimates vary from 15 to 85%, depending on the smoking rates in the study population.

This isn’t all bad news. for some reason, oral cancer patients tend to have better outcomes when their tumours test positive for HPV. at the moment, we don’t know why this is.

How does HPV end up in the mouth?

A few case-control studies have suggested that oral sex may be the main way that HPV ends up in the mouth. One of the largest and best of these studies found that people who had more than six oral sex partners, or more than 26 vaginal sex partners in their lifetime had an increased risk of oral cancer.

But the authors of the this US study themselves concluded

Our data suggest that oral HPV is sexually acquired… but we cannot rule out transmission through direct mouth-to-mouth contact, or through other means.

Indeed one study of around 200 college-age men found that those who had more ‘open-mouth kissing partners’ had a higher risk of getting an oral HPV infection.

But these studies about oral sex or kissing have been small, and their results are not conclusive. up to now, all of the studies on this topic have been ‘case-control studies’. this means that they asked people who had already been diagnosed with oral cancer about their sexual behaviour, often many years ago. this could mean that their responses aren’t entirely reliable. where possible scientists prefer to ask about behaviours in a large group of healthy people, and then look at cancer rates in this group years later (these are known as ‘prospective studies’).

The HPV vaccine and oral cancer

The BBC’s documentary raised the issue of the HPV vaccination and oral cancer. The HPV vaccine protects against two high-risk strains of HPV (16 and 18). it is very effective at preventing cervical cancer and it is already being offered to teenage girls at school.

Some scientists argue that boys should be vaccinated too. High-risk strains of HPV do indeed cause penile and anal cancers in men as well as cervical cancer in women. but studies suggest that, overall, vaccinating males wouldn’t be an effective use of NHS resources, as long as enough women agree to have the vaccine.

If the vaccine also protects against oral cancer, that could change things. but it’s too early to jump to that conclusion because scientists don’t know yet whether the vaccine could prevent HPV infection in the mouth.

So where does that leave us?

Certainly oral cancer is on the increase, and HPV appears to be playing a role. but there are still a lot of unanswered questions about oral sex, human papillomavirus and oral cancer.  for example, we still need to find out:

• How exactly do people contract HPV infections in their mouths, and how does that affect their risk of mouth cancer? we need large studies to answer this question.
• How common are oral HPV infections in the UK? what happens to these infections? how many of them clear up by themselves and how many persist?
• How long does it take for an infection to lead to oral cancer? and in the meantime, are these signs that doctors and dentists could look for to help screen for the disease?
• Is the HPV vaccine effective against oral HPV infections? does this affect decisions about the age at which girls are vaccinated and whether boys should be vaccinated too?

Scientists from across the world, including many funded by Cancer Research UK, are working hard to answer them.

Hazel Nunn is a senior health information manager at Cancer Research UK

this entry was posted on Monday, January 10th, 2011 at 9:00 pm and is filed under Cancer in the news, HPV, Mouth, Risks & Causes. you can follow any responses to this entry through the RSS 2.0 feed. you can skip to the end and leave a response. Pinging is currently not allowed.

Dear Dr. Gott: in your article about abdominal pain, I think you might have missed a likely possibility: gallbladder disease.

I suffered from this for years, and no doctor took me seriously because I didn’t have gallstones. when I finally had my gallbladder removed, I didn’t have any more pain. Estrogen is known to irritate the gallbladder, and a 15-year-old has considerable estrogen in her body.

Dear Reader: Gallbladder disease is another cause of abdominal pain. The pain is typically on the upper right side of the abdomen and may worsen after eating, especially fatty foods.

Nausea, vomiting and loss of appetite may also be present.

There are several types of gallbladder disease that include gallstones, inflammation, infection and blockage/obstruction. two or more of these can be present at the same time. for example, inflammation can lead to blockage, which can lead to infection, or gallstones can lead to blockage, which can then lead to infection.

Symptoms may be reduced by making dietary changes. These can include eliminating suspected food allergens; increasing intake of fiber, fruits and vegetables; and reducing the intake of refined and fatty foods, trans fats, red meat, alcohol and tobacco.

Further treatment depends on which type of gallbladder disease is present.

Gallstones can be treated with medication to dissolve the stone, but this can take up to two years and the stones often recur. Chronic issues with stones and inflammation more often necessitate surgery to remove the stones or the entire gallbladder.

Dear Dr. Gott: your article about the undiagnosed stomach problems sounded exactly like my niece. She suffered for several years until she saw an allergist, who found that she had many food allergies. As long as she avoids those foods, she is pain-free.

Dear Reader: I received three other letters similar to yours. two of those also mentioned H. Pylori, along with the food allergies and sensitivities.

H. Pylori is a common type of bacteria thought to be present in about half of the world’s population.

Most people do not exhibit symptoms, nor do they experience any complications; however, for others, it can lead to potentially serious problems.

Symptoms include weight loss, bloating, nausea, vomiting, frequent burping and an ache or burning pain in the abdomen. Complications include ulcers of the stomach and small intestine, stomach cancer and inflammation of the stomach lining.

Treatment consists of antibiotics and medications to reduce stomach acid. further testing to determine whether the infection has been eradicated may be recommended.

Food sensitivities are food allergies. The different names come into play because allergies conjure up thoughts of hives, rashes, swollen throats and tongues, and classic allergic reactions.

Write to Dr. Gott, c/o NEA-United Media, 200 Madison Ave., Fourth Floor, New York, N.Y. 10016.