Major breakthrough in cancer caused by oral sex – as cases continue to climb in under 50s

Thousands of patients with cancers of the head and neck have been thrown a lifeline by ‘world changing’ drug that dramatically slows the spread of the disease. 

The injection, called pembrolizumab, helps the immune system spot hidden cancer cells in the body. 

It is currently offered to NHS patients with advanced lung, breast and cervical cancers—but expert believe it hold far wider promise. 

Also known by the brand name Keytruda, a groundbreaking trial found the drug kept head and neck cancers at bay for five years compared to 30 months with standard treatments, including surgery, chemotherapy and radiotherapy.

It also slashed the risk of the disease returning elsewhere in the body. 

Researchers presenting the findings at the American Society of Clinical Oncology conference in Chicago said the injection ‘could change the world for these patients’ offering them ‘years longer than the current standard treatments’.  

Head and neck cancer is an umbrella term for cancers of the mouth, throat, voice box, nose, sinuses and salivary glands.

Until recently, experts believed the main causes were lifestyle-related—particularly smoking and heavy drinking.

In recent years, research has suggested that human papillomavirus (HPV) may be responsible for up to 70 per cent of head and neck cancers.

HPV is a common virus spread through close contact, including sex, and is usually harmless. However, in some cases—for reasons not fully understood—it can trigger cancerous changes in healthy tissue.

The virus is already known to cause cervical, anal and penile cancers.

A rise in head and neck cancers, particularly among younger and middle-aged patients, has been linked to oral sex. 

In the global trial, carried out across 24 countries involving more than 700 head and neck cancer patients, 363 received pembrolizumab followed by standard treatment. 

The remainder had standard treatment only. 

Pembrolizumab is a checkpoint inhibitor—it works by helping the immune system recognise and fight cancer.

Scientists found the cancer returned in half the patients given pembrolizumab after five years, compared with two-and-a-half years in those receiving standard care.

After three years, the risk of cancer returning somewhere else in the body was also 10 per cent lower among those on pembrolizumab.

Kevin Harrington, a professor of biological cancer therapies at the Institute of Cancer Research, London, and consultant oncologist at the Royal Marsden NHS Foundation Trust, said: ‘For patients with newly-diagnosed, locally-advanced head and neck cancer, treatments haven’t changed in over two decades.

‘Immunotherapy has been amazingly beneficial for patients with cancer that has come back or spread around the body but, until now, it hasn’t been as successful for those presenting for the first time with disease which has spread to nearby areas.

‘This research shows that immunotherapy could change the world for these patients—it significantly decreases the chance of cancer spreading around the body, at which point it’s incredibly difficult to treat.’

Professor Harrington added that the drug ‘dramatically increases the duration of disease remission—for years longer than the current standard treatments’.

‘It works particularly well for those with high levels of immune markers, but it’s really exciting to see that the treatment improves outcomes for all head and neck cancer patients, regardless of these levels,’ he said.

Laura Marston, 45, from Derbyshire was diagnosed with stage four tongue cancer in 2019 after an ulcer on her tongue didn’t heal. She was later referred to The Royal Marsden where she joined the trial.

‘I was so excited to be on a clinical trial and knowing I was in the best hands was really reassuring,’ she said. 

‘As part of the trial I underwent two rounds of immunotherapy before undergoing surgery.

‘In the months following my surgery I had to relearn how to eat and talk again while also having ten more infusions of immunotherapy, chemotherapy, and radiotherapy. 

‘My clinical team were amazing and went above and beyond for anything I needed. I am amazed I am still here six years later, this treatment has given me the gift of life.’

Cancers that affect the head and neck are the eighth most common form of cancer overall in the UK, although they are two to three times more common in men than in women. 

About 12,500 new cases are diagnosed each year, according to Cancer Research UK, and incidences are on the rise. 

Dr Lyndsy Ambler, Cancer Research UK senior strategic evidence manager, said: ‘Around 4,100 people die from head and neck cancers every year—that’s approximately 11 deaths every day. 

‘Any potential new treatment options for a disease where there has been limited progress for decades are very welcome.

‘Pembrolizumab’s potential benefit for people with head and neck cancer could represent a significant step forward in how we treat the disease.’