The study (Head & Neck, published online Sept. 15, 2009) looked at patients with nasopharyngeal cancer, a tumor that grows behind the nose and at the top of the throat, above the tonsils. This rare cancer occurs in less than 1 of every 100,000 Americans.
“Though rare, this is the first report of nasopharyngeal cancer being caused by the HPV epidemic. We are in the middle of a tonsil cancer epidemic, seeing many patients with tonsil cancer linked to HPV. It turns out that HPV may also be a new cause of this rare form of cancer that occurs in this hidden location,” said study author Carol Bradford, M.D., professor and chair of otolaryngology at the U-M Medical School.
In the study the researchers looked at tissue samples taken before treatment for either nasopharyngeal cancer or tonsil cancer. Of the 89 patients in the study, five had nasopharyngeal cancer, and four of those were positive for HPV.
At the same time, the four HPV-positive tumors were also all negative for Epstein-Barr virus, which has previously been one of the biggest infectious causes of nasopharyngeal cancer.
“Since I began studying head and neck cancer, I have wondered what the cause of Epstein-Barr virus-negative nasopharyngeal tumors might be. This research suggests that there is a changing etiology for nasopharyngeal cancer in the North American population that may mirror the HPV-positive epidemic of tonsil cancer,” said study author Thomas Carey, Ph.D., professor of otolaryngology and pharmacology and co-director of the head and neck oncology program at the U-M Comprehensive Cancer Center.
Overall, about 60% of nasopharyngeal cancer patients are alive five years after treatment. In fact, death rates for this type of cancer have declined 4% per year. The researchers suspect one potential reason is that HPV-related tumors are more responsive to chemotherapy or radiation than tumors linked to the Epstein-Barr virus.
Because nasopharyngeal cancer is so rare, the authors propose a multi-center trial to recruit more patients to verify the role of HPV in nasopharyngeal cancer.
Earlier this year the role of the relationship between HPV and head and neck cancer was also discussed at a news conference held by the American Association for Cancer Research, according to a story on WebMD.
Increasing rates of HPV infection, spread through oral sex, is largely driving the rapid rise in oropharyngeal cancers, which include tumors of the throat, tonsils, and base of the tongue, said Scott Lippman, MD, who chairs the thoracic department at the University of Texas M.D. Anderson Cancer Center, in the story.
“The percentage of oropharyngeal cancers that are HPV positive is much higher now than it was 20 years ago,” he said. “This is a real trend, and that is why there is concern of an epidemic given that fact that oropharyngeal cancer is increasing at an alarming rate,” he added. “Changing sexual practices over the last 20 years, especially as they relate to oral sex, are increasing the rate of head and neck cancers and may be increasing the rates of other cancers as well.”
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