Etiological factors of laryngeal cancer

In order to evaluate the etiological factors, all 318 cases of laryngeal cancer diagnosed during the period of 1962-91 in the Tampere University Hospital area with a population of 400,000 were reviewed. Among males the annual age-adjusted incidence decreased significantly from 7.1 to 2.3 per 100,000. No significant difference in the occurrence was found between urban and rural areas. In males the relative risk (RR) was significantly higher in the lower socio-economic groups. In both sexes smokers had significantly higher risk compared to non-smokers. For male smokers RR was 15.5 (95% CI 10.0-25.4) and for female smokers 12.4 (95% CI 3.9-39.5). Changes in smoking habits seem to be the most important factor contributing to the decreasing incidence of laryngeal cancer in Finland, but other factors like changes in dietary and sauna habits may also have some significance.