A few types of cancer have been linked to the human papillomavirus (HPV) infection. Cervical cancer, for example, can occur as a result of unprotected sex with someone who has HPV. In the same way, cancer can eventually occur in the mouth and throat as a result of unprotected oral sex.

HPV doesn’t directly cause cancer, but it can cause changes in the mouth and throat making them more likely to become cancerous in the future. Awareness of this is low, though. A report by the Oral Health Foundation found just 16% of the population associate HPV with mouth cancer.

In the UK, around one in four mouth cancers, and one in three throat cancers, are HPV-related, states the NHS. In younger patients, most throat cancers are now linked to HPV.

The State of Mouth Cancer UK report for 2020/2021 revealed new cases of mouth cancer in the UK reached 8,772 last year – an increase of 58% in the last decade. The report stated that 58% of mouth cancers appear on the tongue and tonsils.

In a recent study, published in the journal Cancer, US-based researchers polled 508 people about their health and sexual habits. Higher levels of cancer risk were associated with performing oral sex with many different partners in a short period of time, as well as having oral sex at a younger age.

Those who had older sexual partners in their youth were also at greater risk of HPV-related oropharyngeal cancer.

Dental hygienist Anna Middleton, who runs London Hygienist, said the latest body of research is “incredibly concerning” – but also not a surprise, as there have been increasing cases linking HPV to oral cancer in young people in recent years – “so much so, it could supersede alcohol and smoking as a risk associated with oral cancer,” she said.

What can you do about it?

Nobody’s asking you not to have sex – but there are things you can do to prioritise your health at the same time.

One solution is to use protection (a condom or dental dam) when having sex – regardless of whether anal, vaginal or oral. Another is to regularly attend check-ups at sexual health clinics and, if you have a cervix, to attend smear tests.

The third solution is to be mindful of the signs of oral cancer. “Whatever you do, do not ignore any symptoms that last more than three weeks and, if you are worried about coming to clinic due to Covid-19, we can triage patients over video or phone call,” says Middleton.

Here, the hygienist walks us through the key signs to look out for.

Red, white or red and white patches on your tongue or the lining of your mouth 

A white or red patch inside of your mouth or on your tongue could be a potential sign of oral cancer, Middleton suggests, particularly if these patches last more than three weeks.

“These patches often are painless and can easily go undetected – often they are harmless but can equally be precancerous,” she explains. “If you spot any of these patches and your dentist or hygienist is concerned they will refer you to a specialist.”

Ulcers that do not heal after three weeks 

We all get ulcers once in a while, which can be painful for some time before healing on their own. But if they don’t go after three weeks, you should see your GP or a dentist.

“They are usually round or oval sores that appear in the mouth on the cheeks, lips, or tongue,” says Middleton. “In terms of colour, they can be red, yellow, or grey and often swollen.

“It is usually safe to treat mouth ulcers at home. However if your mouth ulcer keeps getting worse, or has not got better after more than three weeks, it could be a sign of oral cancer.”

She suggests ulcers caused by mouth cancer tend to appear on or under the tongue, but you can get them in other areas of your mouth too.

A swelling in your mouth that lasts for more than three weeks 

Likewise, a swelling in the mouth that has been there for more than three weeks is worth getting checked out.

One of the most common causes of swelling in the mouth is an injury or trauma such as eating hard food or getting burnt by hot food or drink, says Middleton, and dehydration can also cause swelling due to a dry mouth. “This can be caused by excessive alcohol consumption, medications, illness or simply not drinking enough water,” she explains.

But HPV can also cause growths in your mouth. “These don’t tend to cause pain, but once discovered need to be treated and removed so that they don’t lead to oral cancer,” she says. By now you’ve probably realised that the general rule is that if something seems abnormal lasts more than three weeks, seek medical attention.

Pain when swallowing 

Lots of us experience sore throats – and pain when swallowing – throughout our lifetimes. However, while rare, pain when swelling can also be a symptom of throat or oral cancer. “If you have had this symptom for a while, or you’re starting to eat softer food, consult your doctor or a dental professional,” says the hygienist.

Feeling like something is stuck in your throat

“Otherwise known as ‘globus pharyngeus’, it is the feeling when you’re unable to remove a lump in your throat, or it feels like something is stuck there but there is no actual obstruction,” says Middleton.

While one common cause is acid reflux, this needs to be confirmed to rule out cancer.

“Typically, cancer of the mouth and throat occurs in those who have risk factors such as smoking, alcohol or a history of HPV. So, if you know you have one of the associated risk factors and have a sore in your mouth that won’t heal, a sensation of something in your throat that won’t go away, fevers or night sweats, or weight loss then seek medical advice,” she adds.

Cancer Research UK notes that, on the whole, only a very small percentage of people with HPV do develop mouth or oropharyngeal cancer.

It’s thought the HPV vaccination for girls (which began in 2007) and boys (which started in 2019), will protect 800,000 children a year from HPV-related cancers and diseases.