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(Drug information on 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, she said.
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.