NHS England has vowed to eradicate cervical cancer by 2040, a landmark goal that would not be possible without the existence of a vaccine against the sexually transmitted human papillomavirus (HPV).
HPV is the biggest cause of cervical cancer, with various strains of the virus linked to 95 per cent of cases. The HPV vaccine is now available free of charge to all women aged under 25 on the NHS, but experts say cervical cancer is not the only type of the disease that can be caused by the virus.
Dr Elizabeth Marsh, associate professor in cellular and molecular biology at the University of Derby, and an expert in HPV positive cancers, says that HPV is a significant contributor to head and neck cancers, especially in men.
She believes that giving HPV vaccinations to 12-13 year-old boys – which the NHS has been doing since 2019 – could eventually drive down rates of these cancers as well. “As of this year, the HPV vaccination programme now vaccinates against nine HPV strains,” says Dr Marsh. “One of these, HPV-16, is responsible for around 90 per cent of HPV-positive head and neck cancers.”
Awareness of the link between strains of HPV and head and neck cancers has been steadily growing over the past six years. In 2017, the World Health Organization formally linked HPV to a specific form of head and neck cancer, called oropharyngeal squamous cell carcinomas (OSCC) or, more simply, oropharyngeal cancer, which affects the tonsils and the base of the tongue.
The area is believed to be particularly vulnerable because the oropharynx, the middle part of the throat, has an uneven surface lined with deep crevices which make an ideal environment in which the virus can lodge.
“Oropharyngeal cancer in men is now more common than cervical cancer in women in the UK and the US,” says Dr Marsh. “The incidence of HPV-positive disease is estimated to be 29,000 global cases per year.”
Concerningly, this trend is being seen first-hand by oncologists such as Dr Shreerang Bhide, a consultant at the Royal Marsden Hospital in north London. “Head and neck cancer incidence is increasing,” he says. “This is because rates of HPV-related cancers are rising and projected to treble over the next few decades.”
Are these cancers linked to increased oral sex?
Ten years ago, Michael Douglas, the Hollywood star, revealed in an interview that he suspected his diagnosis of throat cancer was linked to oral sex. “Without wanting to get too specific, this particular cancer is caused by HPV which actually comes about from cunnilingus,” he told The Guardian.
While Douglas was correct – research suggests HPV is more likely to be spread through cunnilingus compared with fellatio – oral sex is not the only way in which HPV can be transmitted.
In 2021, a study in the journal Cancer looked into the connection between different forms of sexual activity and HPV-associated oropharyngeal cancer. The researchers found that even kissing, and particularly deep kissing, is also linked to heightened risk, with individuals who had 10 or more deep kissing partners twice as likely to develop an HPV-related cancer compared to those who had just one.
People in the study who either suspected or confirmed that their partners had extramarital affairs also faced a higher risk of HPV-associated oropharyngeal cancer.
“HPV-positive head and neck cancer is associated with sexual behaviours, notably oral sex,” says Dr Marsh. “However, while oral sex is indeed a way the virus can be transmitted to the head and neck, it isn’t the only one.”
How does HPV cause neck and head cancer?
HPV infection in the mouth and throat is common. Cancer Research UK says around eight in ten of us will unknowingly become infected with the virus at some point in our lives, usually in our 20s. Research has shown that for the majority of people, the immune system clears the virus within two years, but for a small proportion of individuals, the infection lingers and in some of those cases will become cancerous, sometimes up to 30 or 40 years later.
HPV-16, the strain of the virus associated with cervical cancer and OSCCs, could over time also interfere with the function of various proteins involved in suppressing tumours which could give rise to the onset of cancer, although Dr Marsh cautions that we still have much to learn.
According to Dr Marsh, more than half of the cases of oropharyngeal cancer in the UK are caused by HPV. The rest are linked to other risk factors including smoking and drinking.
What are the signs and symptoms to watch out for?
Oropharyngeal cancer is relatively slow-growing and can take a long time for any symptoms to become noticeable. One of the major signs is a lump in the neck, a bit like a swollen gland, which indicates that it has spread to a lymph node.
“You should see a GP if you develop any new or concerning symptoms such as a lump in the neck or a hoarse voice,” says Prof Stuart Winter, an ear, nose and throat surgeon at GenesisCare, the private cancer care provider.
Do we need better screening?
Dr Bhide predicts rates of oropharyngeal cancer are likely to decrease over time following the decision to make the HPV vaccine available for free on the NHS to all 12-13 year-olds in 2019.
“A person has to be vaccinated prior to being sexually active or getting infected with the virus,” says Bhide. “The latent period between getting infected with the virus and developing cancer is between 10 and 40 years, so it will be a while before we see the benefits of the immunisation strategy.”
Dr Bhide is not convinced about the benefits of screening for the presence of the HPV virus in mouth and throat cavities in the general male population as less than one per cent of those infected with the virus will go on to develop cancer.
However, Dr Marsh believes there is an urgent need for better diagnostic tests at dedicated screening centres or even dental surgeries to identify the disease at a much earlier stage. This is because the signs of oropharyngeal cancer tend to emerge relatively late when the disease is at a more advanced stage.
No such tests are clinically available but earlier this year, researchers at the University of Surrey published a proposed test, called Pandora (point-of-care analysis for non-invasive diagnosis of oral cancer), which could be used to measure samples collected during routine dental appointments. The study showed the test is more than 92 per cent accurate at identifying patients with oropharyngeal cancer, and more than 80 per cent accurate at identifying signs of damage to cells in the throat which could develop into cancer.
What can you do if you’re concerned?
Any men who turned 13 before 2019, will not have received the HPV vaccine and could in theory be at risk of developing HPV-associated oropharyngeal cancer at some point in life.
Dr Marsh recommends checking your mouth and neck once a month, after brushing your teeth. She has produced a self-examination video guide with the University of Derby which suggests checking the inside of your lips, gums, under the tongue and at the back of the mouth for any lumps, bumps, red and white patches or persistent ulcers which have not gone away.
“Early diagnosis doesn’t just save lives, it saves quality of life, so awareness is such an important part of this process,” she says.