Abstract
BACKGROUND: Considerable global variation in the incidence of lip, of oral cavity and of pharyngeal cancers exists. Whilst this reflects regional or population differences in risk, interpretation is uncertain due to heterogeneity of definitions of sites and of sub-sites within this anatomically diverse region. For Australia, limited data on sub-sites have been published. This study examines age-standardised incidence trends and demography from 1982 to 2008, the latest data available. METHODS: Numbers of cases within ICD10:C00-C14 were obtained from the Australian Institute of Health and Welfare, recorded by sex, age, and sub-site. Raw data were re-analysed to calculate crude, age-specific and age-standardised incidence using Segi's world-standard population. Time-trends were analysed using Joinpoint regression. RESULTS: Lip, Oral Cavity and Pharyngeal (excluding nasopharynx) cancers, considered together, show a biphasic trend: in men rising 0.9% pa from 1982 to 1992, and declining 1.6% pa between 1992 and 2008. For females: rises of 2.0% pa 1982-1997; declines of 2.8% pa 1997-2008. Lip cancer is declining especially significantly. When the Oropharynx is considered separately, steadily increasing trends of 1.2% pa for men and 0.8% pa for women were observed from 1982 to 2008. CONCLUSIONS: Although overall rates of lip/oral/oropharyngeal cancer are declining in Australia, these are still high. This study revealed steady increases in cancers of the oropharynx, beginning in the late 1990s. Continued efforts to reduce the burden of these cancers are needed, focused on reduction of the traditional risk factors of alcohol and tobacco, and with special emphasis on the possible role of human papillomavirus and sexual hygiene for cancers of the oropharynx.