Research, which is helpfully summarised on the website of Cancer Research UK, shows that the main causes of oral cancer are tobacco usage and excess consumption of alcohol with their combined usage having a synergistic effect. These factors together account for about 75 per cent. of the 5,300 cases of oral cancer occurring annually in the United Kingdom. There is also evidence of an association with the human papillomavirus and low intake of fresh fruit and vegetables. Tobacco usage and alcohol consumption are also associated with cancer of the oesophagus and larynx, together with diet and family history, but information is not available on which to base estimates of their relative significance.