Exploring trends in laryngeal cancer incidence, mortality and survival: implications for research and cancer control.

South Australian registry data were used to investigate trends in laryngeal cancer age-standardised incidence, mortality and disease-specific survival from 1977 to 2005. Incidence rates decreased by 32% from 1980-84 to 2000-05, affecting both sexes and ages under 70 years. There were concurrent reductions in mortality, although statistical significance was not achieved with the numbers of deaths examined (p>0.05). More than other cancers, laryngeal cancers presented in: the 50-79 year age range; males, particularly those born in Southern Europe; UK/Irish migrants; and residents of lower socio-economic areas. Compared with other cancers, laryngeal cancers were less common in more recent diagnostic periods. The ratio of glottis to other laryngeal cancers was higher in males, older patients, and those born in Southern Europe, UK/Ireland and Western Europe. A secular increase in this ratio was evident. The five-year survival from laryngeal cancer was 68%, with poorer outcomes applying for older patients, non-metropolitan residents, patients with cancers of laryngeal sub-sites other than glottis, and potentially patients born in Southern Europe. Secular changes in survival were not observed. Reductions in incidence are attributed to decreases in tobacco smoking in males and reductions in per capital alcohol consumption since the 1970s. The higher ratio of glottis to other laryngeal cancer sub-sites in males may indicate a greater contribution made by tobacco, as opposed to alcohol, in males. The lower survival observed in non-metropolitan patients may reflect poorer access to radiation oncology and other specialist services, although delays in diagnosis for other reasons may have contributed.