Background: There is a growing recognition of the involvement of human papilloma virus infection in the etiology of head and neck cancers at some sites, mainly the base of the tongue, tonsils, and other oropharynx (hereafter termed oropharyngeal cancer). Other oral sites (hereafter termed oral cavity cancer [OCC]) show a stronger association with tobacco and alcohol. Little is known about the ethnic variation in incidence for these cancers. This study determined incidence rates of OCC and oropharyngeal cancer among South Asian, Chinese, and the general population in British Columbia, Canada.
Methods: Patients with OCC and oropharyngeal cancer diagnosed from 1980 to 2006 were identified through the British Columbia cancer registry, and surname lists were used to establish ethnicity. Age-adjusted incidence rates were determined for these cancers by sex, topographical site, and ethnicity, and temporal trends were examined.
Results: Age-adjusted incidence rates have been decreasing for OCC and increasing for oropharyngeal cancer in the general population for both sexes, with men having higher incidence rates than women. Ethnic differences were found, with the highest age-adjusted incidence rates for OCC for men in South Asians and for women in Chinese, and with the highest age-adjusted incidence rates for oropharyngeal cancer for men in Chinese and for women in the general population. Differences were also found for OCC topographical sites by sex and ethnicity.
Conclusions: The incidence of oropharyngeal cancer has now surpassed OCC in the British Columbia male population. Ethnic minorities are at higher risk than the general population for both OCC and oropharyngeal cancer for men, and for OCC for women.
(c) 2010 American Cancer Society.