VACCINATING schoolboys in Scotland against the potentially deadly human papillomavirus (HPV) has the potential to slash cases of head and neck cancer among men in the future, according to a major new study.

For the first time in Scotland, researchers analysed tumours from head and neck cancer patients to determine how many tested positive for the virus, which is better known for it association with cervical cancer.

The scientists, from Glasgow Caledonian, Glasgow and Strathclyde universities, examined 235 patients from the Greater Glasgow and Clyde region who had been diagnosed with oropharyngeal cancer, which affects the part of the throat directly behind the mouth.

Over a two year period from 2013 to 2015, they found that 78 per cent of cases had occurred among men. Of those, 60% tested positive for the HPV virus, with the most commonly present strain being HPV type 16 - one of four strains which the NHS vaccine, Gardasil, protects against.

Read more: School HPV vaccination delivering 'dramatic' cuts in cervical disease 

The HPV vaccination has been routinely available to schoolgirls through Scotland's national immunisation programme since 2008, but in July 2018 the Scottish Government confirmed that it would extend HPV vaccination to schoolboys as well.

There is no date yet for its introduction, but Public Health Minister Joe Fitzpatrick said it would be rolled out "as soon as practicable" in conjunction with Health Protection Scotland and NHS Scotland.

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However, the findings today indicate that some of the benefits already seen in relation to a reduction in cervical disease among women could be replicated in relation to head and neck cancers in men.

Co-author Dr Kevin Pollock, of GCU, said: “Our latest data shows that 78% of people with head and neck cancers were men and that HPV was present in 60% of the cancers. This means the vaccine may reduce some of these cancers in the long term in Scotland.

"Not only that but when we looked at the deprivation status of these cases – much like cervical cancer – head and neck cancers are disproportionately experienced by more deprived individuals.

"We know that smoking and alcohol consumption are linked to these cancers and policies are in place to try and reduce this consumption but the great thing about a vaccine given to young boys is that if you give it early enough and see a high uptake across in all the deprived areas you are reducing the inequality.”

Read more: HPV vaccine to be rolled out to boys in Scotland 

Head and neck cancer has been increasing over last 25 years, particularly amongst men. In 1994, there were 100 cases in Scotland but by 2015 the numbers had soared three-fold to 350, with incidence particularly high in the west of Scotland.

Dr Pollock added: “Some of the reasons for this increase are due to alcohol and smoking but we think the proportion of HPV-related head and neck cancers are increasing. This might be due to a change in sexual behaviours.”

When the authors analysed cases of head and neck cancer in the Scottish Cancer Registry over the past 40 years, they found a changing pattern for the disease.

The rate of laryngeal cancer, which is strongly associated with tobacco consumption, has remained essentially stable. Oral cancer, which is associated with alcohol consumption, is steadily increasing.

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However, oropharyngeal cancer has risen comparatively more rapidly and is projected to rise further. Public health experts must take account of the "dramatic and relatively new role of HPV", say the researchers.

HPV is an extremely common sexually-transmitted virus, present in around 80% of the population at any one time.

In most cases, the body's immune system can fight it off but when that does not happen it can lie dormant and eventually lead to cancer.

Previous studies worldwide have shown that the prevalence of high-risk HPV strains in oropharyngeal tumours ranges from 6.1% in Spain and 38% in the Netherlands to 62% in Denmark.

US estimates are consistently higher at around 60 to 70%, whereas in South America fewer than 5% of oropharyngeal cancer cases tested positive for HPV.

In April, Dr Pollock and colleagues hailed the effectiveness of the HPV jab after their study revealed that routinely vaccinating schoolgirls in Scotland had led to a “dramatic” drop in cervical disease later in life.

The researchers found the vaccine has nearly wiped out cases of cervical pre-cancer in young women since an immunisation programme was introduced 10 years ago.

While they recommend extending the HPV vaccine to boys, they say it should not be done alone.

They write: "Although primary prevention of most [oropharyngeal cancers] through vaccination will probably exert a significant influence on the burden of this disease in time, in the shorter term, Scotland must address other interventions to promote healthy living in order to reduce excessive alcohol consumption and smoking. 

"Such interventions, if successfully implemented, would have far-reaching benefits beyond the reduction of oropharyngeal cancers."

The study is published in the Royal College of Radiologists' journal 'Clinical Oncology', published by Elsevier.