Study proves HPV virus can lead to throat cancer
Infection with certain types of the HPV virus significantly increases the risk of throat cancers, a study has shown.
Experts at Oxford University compared blood samples from 938 patients with head and neck, oesophageal (gullet) and oropharyngeal (back of throat) cancers with 1,599 people without the disease.
HPV – the human papilloma virus – can spread through oral or genital contact. People who have had a number of oral sex partners have a higher risk of being infected.
The researchers found that more than a third of those who had oropharyngeal cancers also carried antibodies to one of HPV's key cancer-causing proteins, a protein from the HPV16 virus called E6.
These antibodies could be detected in patients' blood even in samples taken more than 10 years before the cancer was diagnosed. By comparison, less than 1pc of people without cancer carried the antibodies in their blood.The E6 protein disables the p53 protein, which is often called the "guardian of the genome" because it protects cells from DNA damage and cancer development.
Having antibodies against this HPV protein indicates that HPV's cancer-causing processes have been activated before.
Hollywood actor Michael Douglas last month spoke of the link between cancer and HPV when discussing his own battle with throat cancer.
Scientists in the Oxford study estimated that around seven in 100 non-smoking women and around 23 in 100 non-smoking men who carry the E6 antibody will develop oropharyngeal cancer over 10 years.
But patients with oropharyngeal cancers linked to having the HPV infection were more likely to survive than people whose cancers were not related to the infection.
Some 84pc of people with the HPV16 antibodies in their blood were still alive five years after diagnosis compared with 58pc of people without them. HPV is already known to increase the risk of developing cervical, vulval, anal and penile cancers.
Girls in first year in Irish secondary schools are offered a free HPV vaccine by the HSE. The vaccine is called Gardasil and protects against the types of HPV that cause seven out of 10 cervical cancers.
Dr Ruth Travis, one of the authors of the Oxford study, said: "These results provide some evidence that HPV16 infection may be a significant cause of oropharyngeal cancer."
The study is published in the 'Journal of Clinical Oncology'.