Antibodies to a high-risk type of human
papillomavirus (HPV16) that causes mouth and throat
cancers when transmitted via oral sex can be
detected in blood tests many years before the
clinical onset of the disease, reveals a new study
from the International Agency for Research on Cancer
(IARC) in cooperation with the German Cancer
Research Center (DKFZ) and the United States
National Cancer Institute (NCI) in an article
published online by the Journal of Clinical Oncology.
According to the results of the study, HPV16 E6
antibodies in the blood indicate a very high risk of
developing an HPV-associated cancer of the
oropharynx.
“These results are very encouraging. Up to now, it
was not known whether these antibodies were present
in blood before the cancer became clinically
detectable. If these results are confirmed, future
screening tools could be developed for early
detection of the disease,” explained Dr Paul Brennan,
Head of the Genetics Section at IARC and the senior
author of the study. “To date there are no available
markers for early detection of this cancer,” he said.
Although HPV is better known for causing cervical
cancer and other genital cancers, it is also
responsible for an increasing number of cancers of
the mouth and throat, particularly amongst men, and
about 30% of oropharyngeal cancers worldwide are
estimated to be HPV-related. The main type of HPV
associated with these cancers is HPV16.
The issue was highlighted by Hollywood actor Michael
Douglas, who said his throat cancer was caused by
HPV transmitted through oral sex.
Oropharyngeal cancer includes cancers of the tonsils,
the oropharynx (the oral part of the pharynx), the
soft palate, and the base of the tongue.
Oropharyngeal cancer has been a relatively uncommon
cancer, traditionally associated with heavy tobacco
smoking and heavy alcohol consumption. But over the
past few decades its occurrence has increased
dramatically in many parts of the world, especially
in Europe and North America. This increase is
thought to be due to the growing number of
infections with HPV and to changing sexual practices,
such as an increase in oral sex.
In the new study, of the 135 individuals who
developed oropharyngeal cancer, 47 (about one third)
had HPV16 E6 antibodies in their blood up to 12
years before the onset of disease, compared with
only 9 of 1599 individuals who did not develop the
cancer (less than 1%). All participants were part of
the European Prospective Investigation into Cancer
and Nutrition (EPIC) study, which comprises more
than 500 000 individuals from 10 European countries
who were recruited in the 1990s and have been
followed up since then.
Another significant finding of this landmark study
was that patients with oropharyngeal cancer who had
tested positive for antibodies against HPV16 E6
before cancer diagnosis were 3 times as likely to be
alive 5 years after their diagnosis as those
oropharyngeal cancer patients who had tested
negative for these antibodies.
“The work shows how innovative laboratory tests may
help us develop tools to prevent or detect cancer
early as well as improve treatment of the disease”
said Dr Christopher Wild, Director of IARC.
For more information
IARC
(MDN)
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