By Dr. Henry N. Ho, Director, Head and Neck Program, Florida Hospital Cancer Institute
I recently attended the American Society for Radiation Oncology Multidisciplinary Head and Neck Cancer Symposium held in Phoenix, Arizona from Jan. 26-28, 2012. By far the presentation generating the most interest was by Maura Gillison, et. al. from Ohio State University titled: “Prevalence of Oral HPV Infection in the United States, 2009-2010” which appeared in JAMA, Jan. 26, 2012. In fact, the USA Today covered the story Jan.27, 2012 on page 3A. This was the first study to evaluate the national epidemiology of oral HPV infection in the U.S. Saliva samples and questionnaires were analyzed from 5,579 study participants aged 14 through 69.
Oral human papilloma virus infection is the cause of a portion of oropharyngeal squamous cell carcinoma (OSCC). HPV positive OSCC is associated with sexual behavior wheras HPV negative OSCC is associated with chronic tobacco and alcohol use. Almost all HPV+ OSCC cases are associated with HPV type 16 and oral infection with this type confers a 50 fold risk increase of developing HPV+ OSCC. Of concern is that the incidence of HPV OSCC has increased by 225% from 1988 to 2004 from 0.8 to 2.6 cases per 100,000 population.
The Gillison group found that 10.1% of males and 3.6% of females had oral HPV infection. The rate of infection for HPV 16 was 1%, which translates to 2.13 million people in the U.S. Sexual behavior was shown to be a risk factor to acquiring infection with prevalence rising to 20% among those with greater than 20 lifetime sexual partners. In addition, the study showed that HPV infection is sexually transmitted, as sexually active people have an 8 fold higher risk of infection as compared to the sexually inexperienced. Men were more at risk as they had 3 times the risk of HPV infection than women and 5 times the risk of having HPV 16 infection.
The U.S. Centers for Disease Control and Prevention currently recommends routine vaccination against HPV for females aged 9 through 26 and males aged 9 through 21 for prevention of genital warts and anogenital cancer. Clinical trials to show efficacy against oral HPV infection are, so far, lacking. The U.S. Cancer Registry data estimates that the number of oropharyngeal HPV related cancers will exceed that of invasive cervical cancer by the year 2020, which currently stands at approximatedly 12,000 cases per year.
The looming challenge will be to ideally manage this growing number of younger, healthier cancer sufferers. The Florida Hospital Cancer Institute Head and Neck Program is taking steps to meet the challenge by developing the latest therapeutic techniques such as transoral robotic surgery or TORS. This sophisticated tool is specifically suited for cancers of the oropharynx. Our experience with it is rapidly growing and initial results have been gratifying. Refining the technique and its role, as it relates to the other treatment modalities of radiation and chemotherapy, is a constant goal.