Monday, May 9, 2011

HPV Shown to Cause Head/Neck Cancers

Since the discovery in 1984 that HPV (Human Papillomavirus) was responsible for cervical cancer, research has continued to prove the connection between HPV and cancers in other areas of the body.

It has been known for quite some time now that HPV is also responsible for dysplasias (abnormal cells) and cancer of the vulva, vagina, and the penis in men. In the last decade, the connection has also been made between HPV and anal cancer. More recent research has pointed to HPV as being the cause of a high percentage of oral and throat cancers.

In a study performed at the John’s Hopkins Oncology Center, twenty-five percent of the 253 patients included in the study and having been diagnosed with head and neck cancers were positive for HPV. Of those, HPV16 (considered to be one of the most aggressive strains of the virus) accounted for ninety percent of the cases. These results were published in the New England Journal of Medicine, May 2008. According to Dr. Maura Gillison of John’s Hopkins, HPV16 accounted for a thirty-two fold increase in risk for oropharyngeal squamous cell cancers. Subsequent studies have shown the percentage of HPV related tumors to be as high as sixty-four percent.

In a paper presented to the American Society of Clinical Oncology in 2009, patients have a better chance of survival, by more than fifty percent, if their tumors contain HPV than if they don’t. The differences between those oropharyngeal cancers caused by HPV and those caused by other factors such as prolonged cigarette smoking, alcohol consumption and the chewing of tobacco are so marked, it is suggested that they be treated as two different types of cancer.

Researcher at the Roswell Park Cancer Institute in Buffalo New York indicates that since 1989 they have had a three-fold increase in the number of throat cancers they treat. This according to Dr. Thom Loree, Chair of the Department of Head and Neck Surgery. They also advocate a national discussion regarding providing the HPV vaccine to both young men and women in an effort to prevent these head and neck cancers. Their data shows that those patients whose cancers were HPV related were about fifty to sixty percent.

Since its approval by the FDA (Food and Drug Administration) in 2006, the Gardasil vaccine’s indication for use has changed numerous times to allow for the inclusion of the prevention of various other cancers. It appears that the vaccine may well prevent oropharyngeal cancers as well. Currently, the number of individuals who actually go on to complete the three shot series for the vaccine is a meager thirty percent in the United States. It will be interesting to see if these numbers increase when the focus shifts away from a sexually transmitted infection to a head or neck cancer.