Occupational Variation in the Incidence of Laryngeal Cancer in the Nordic Countries

INTRODUCTION: Laryngeal cancer (LC) constitutes almost one third of the head and neck cancers, and its main risk factors, alcohol use and smoking, are well established. Our aim was to explore the variation in the incidence of LC between different occupations. METHODS: This study was based on data from the Nordic Occupational Cancer Study (NOCCA), involving 14.9 million individuals from Denmark, Finland, Iceland, Norway, and Sweden. Occupational data from censuses were linked to cancer registry data from a period of up to 45 years (21,166 LC diagnoses) using personal identity codes. Standardized incidence ratios (SIRs) were calculated for different occupations, using the respective national populations as a reference. RESULTS: Of the 21,166 patients with LC, 18,488 (87%) were men. The highest SIRs in men were noted among waiters (3.31, 95% confidence interval [CI] 2.69-4.02), beverage workers (2.51, 95% CI 1.91-3.24), and cooks and stewards (2.25, 95% CI 1.82-2.74). Among women, the highest SIRs were observed among building hands (7.37, 95% CI 3.53-13.55) and public safety workers (3.60, 95% CI 1.17-8.40). Farming and teaching occupations showed reduced SIRs in both sexes. The SIRs among male farmers, teachers, gardeners, and technical workers were reduced in all countries. The SIRs remained elevated and stable among cooks and stewards, waiters, packers, seamen, sales agents, and economically inactive males across the three 15-year periods from 1961 to 2005. CONCLUSION: The study confirms a major variation in the incidence of LC between occupations. The findings underscore the importance of considering lifestyle factors typical of each occupation in cancer risk assessments and the potential benefits of targeted prevention efforts.