Washington, Oct 8 The increased incidence of a rare type of head and neck cancer is linked to HPV, or human papillomavirus, according to researchers at the University of Michigan Comprehensive Cancer Center.

In their study, the scientists looked at patients with nasopharyngeal cancer- a tumour that grows behind the nose and at the top of the throat, above the tonsils.

"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 Dr. Carol Bradford.

For the research, researchers examined tissue samples taken before treatment for either nasopharyngeal cancer or tonsil cancer.

Out 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 tumours 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 Dr. Thomas Carey, Ph.D.

The study has been published online in the journal Head and Neck. (ANI)