Incidence of oropharyngeal cancer on the rise

NCI scientists report that the incidence of oropharyngeal cancer significantly increased during the period 1983-2002 among people in countries that are economically developed. Oropharyngeal cancer occurs primarily in the middle part of the throat behind the mouth, including the base of the tongue, the side and back walls of the throat, and the tonsils. The results of this study, by Anil K. Chaturvedi, Ph.D., Division of Cancer Epidemiology and Genetics, NCI, and his colleagues, appeared online in the Journal of Clinical Oncology, Nov. 18, 2013.

Recent studies from several countries have reported rising incidence of oropharyngeal cancers and subsequent studies have shown the human papilloma virus (HPV) as the potential cause. However, it has been unclear whether this increase in oropharyngeal cancer incidence represents a global phenomenon. Chaturvedi and his collaborators at Ohio State University and the International Agency for Research on Cancer evaluated incidence trends for oropharyngeal and oral cavity cancers. Their analysis was based on cancer registry data from more than 180,000 patients in 23 countries. They found that oropharyngeal cancer incidence increased overall among both women and men from1983 to 2002, almost exclusively in economically developed countries. Among women, in all countries with significant increases in oropharyngeal cancer incidence, there was also an increase in incidence of both oral cancer and lung cancer, two cancers strongly associated with smoking. In contrast, among men, rising oropharyngeal cancer incidence was generally accompanied by decreases for oral cancer and lung cancer. These observations among men suggest some factor other than smoking, perhaps infection with HPV, as a potential explanation for rising oropharyngeal cancer incidence. Researchers note that prophylactic HPV vaccine has been shown to protect against oral HPV infection, suggesting an additional benefit of vaccination programs for both women and men.