Oral sex may be to blame for rise in mouth cancer

The rapid rise in cases of oral cancer caused by a virus transmitted during oral sex has serious implications for health services around the world, warn researchers.

They suggest that the sexual transmission of HPV might be the reason for the rise.

Despite an overall marginal decline in most head and neck cancers in recent years, the level of oropharyngeal squamous cell carcinoma (OSCC) has increased greatly, especially in the developed world.

In the US, cases increased by 22% between 1999 and 2006, after showing no change between 1975 and 1999, while the UK has seen a 51% increase in oral and oropharyngeal cancer in men between 1989 and 2006.

This increase seems to be accounted for by a rise in HPV-related tumours, say the authors, led by Hisham Mehanna at the Institute of Head and Neck Studies and Education, University Hospital, Coventry.

A recent study showed a 70% increase in the detection of HPV in biopsies taken to diagnose oropharyngeal carcinoma in Stockholm since the 1970s.

HPV-related oropharyngeal carcinoma has also been reported in 60-80% of recent biopsy samples in studies conducted in the US, compared with 40% in the previous decade.

HPV-related oropharyngeal carcinoma seems to be a new and distinct disease entity, explain the authors.

It has a better prognosis than non-HPV related oropharyngeal carcinoma, particularly in non-smokers, but the reason for this improved survival is not fully understood.

They suggest that sexual transmission of HPV might be the reason for the rise.

A recent study found that the risk of developing oropharyngeal carcinoma was associated with a history of six or more lifetime sexual partners, four or more lifetime oral sex partners, and – for men – an earlier age at first sexual intercourse.

But, whatever the reason, the rising rate of HPV related oropharyngeal carcinoma has implications for health service providers and commissioners, they warn.

For instance, patients are typically younger and employed, and – because outcomes seem to be more favourable than for patients with non-HPV related carcinoma – they will live longer.

Consequently, they need prolonged support from health, social, and other services, and may require help in returning to work.

There are also public health implications, they add. For example, including boys in HPV vaccination programmes before they become sexually active.

They write: ‘At present, we have no good evidence to support managing patients with HPV related head and neck cancer differently from those whose tumours are not HPV related, although several studies are being planned to evaluate different treatment options. Until data from such studies are available, we suggest that clinicians should not change their current treatment policies, but should aim to offer all patients with oropharyngeal cancer the opportunity to enrol in an appropriate clinical trial.’

Elsewhere around the globe, researchers from the University of Sydney found that almost two thirds of all throat and tonsil cancer cases are caused by the HPV virus.

Research now suggests the HPV, which is transmitted by oral sex, could soon rival smoking and drinking as a main cause of mouth cancer.

The findings from Australia could also suggest an increasing practise of oral sex.