BALTIMOREResearchers at the Johns Hopkins School of Medicine
and School of Hygiene and Public Health have found human
papillomavirus (HPV) to be a likely cause of certain cancers of the
head and neck, and also an indicator of improved survival.
The investigators studied 253 patients, aged 17 to 91, with newly
diagnosed or recurring squamous cell head and neck cancer. HPV was
detected in 62 tumors (25%). Of the HPV-positive tumors, 90%
contained HPV-16, a high-risk, tumor-promoting form.
Somewhat unexpectedly, those with HPV-positive tumors were 60% less
likely to die of their cancer than those with HPV-negative tumors,
said Maura L. Gillison, MD, lead author of the study (J Natl
Cancer Inst, May 3, 2000). The average survival of patients with
HPV-positive tumors was 91 months or more but only 76 months among
those with HPV-negative tumors.
These data suggest that HPV-positive head and neck cancers may
comprise a distinct molecular, clinical, and pathologic disease, very
different from other types of the disease, Dr. Gillison said.
Up to 80% of squamous cell head and neck cancers are linked to
tobacco and alcohol use. However, in this study, patients with
HPV-positive tumors in the oropharynx were light- or nondrinkers and
nonsmokers. We believe that HPV infection of the upper airway
may be the cause of tumor development in this group of people,
HPV may cause these cancers by producing two oncoproteins known as E6
and E7, which, in turn, inactivate the p53 and Rb tumor-suppressor
genes, Dr. Gillison said.
The researchers are planning a clinical trial of a cancer vaccine
used for HPV-associated cervical cancers in these HPV-positive head
and neck cancers. The vaccine would be given prior to standard
therapy with surgery and/or radiation therapy.