Strengthening the prevention of oral cancer: the WHO perspective.

Cancer is one of the major threats to public health in the developed world and increasingly in the developing world. In developed countries cancer is the second most common cause of death. According to the World Health Report 2004 (1), cancer accounted for 7.1 million deaths in 2003 and it is estimated the overall number of new cases will rise by 50% in the next 20 years (2). Oropharyngeal cancer is more common in developing than developed countries (3, 4). The prevalence of oral cancer is particularly high among men, the eighth most common cancer worldwide. Incidence rates for oral cancer vary in men from 1 to 10 cases per 100 000 population in many countries. In south-central Asia, cancer of the oral cavity ranks among the three most common types of cancer. In India, the age standardized incidence rate of oral cancer is 12.6 per 100 000 population. It is noteworthy that sharp increases in the incidence rates of oral/pharyngeal cancers have been reported for several countries and regions such as Denmark, France, Germany, Scotland, central and eastern Europe and to a lesser extent Australia, Japan, New Zealand and the USA (3, 4). The cancer epidemic in developed countries, and increasingly in developing countries, is due to the combined effect of the ageing of populations, and the high or increasing levels of prevalence of cancer risk factors. It has been estimated that 43% of cancer deaths worldwide are due to tobacco, unhealthy diet, physical inactivity and infections (3). Tobacco use and excessive alcohol consumption have been estimated to account for about 90% of cancers in the oral cavity; the oral cancer risk increases when tobacco is used in combination with alcohol or areca nut (5). The evidence that smokeless tobacco causes oral cancer was confirmed recently by the International Agency for Research on Cancer (6).