Occupation and risk of oesophageal adenocarcinoma and squamous-cell carcinoma: The Nordic Occupational Cancer Study.

To assess associations between occupation and risk of oesophageal adenocarcinoma (AC) and squamous-cell carcinoma (SCC), data from the Nordic Occupational Cancer Study, a large population-based cohort with long-term follow-up, was used. The Nordic Occupational Cancer Study includes 12.9 million individuals aged 30-64 years who participated in national censuses in Finland, Iceland, Norway and Sweden in 1960-1990. Individuals were assigned to one of the 54 occupational categories, and individuals with oesophageal cancer were identified through nationwide cancer registries with follow-up through 2005. Country-specific standardised incidence ratios (SIRs) with 95% confidence intervals (CIs) were estimated. During follow-up, 4,722 ACs and 14,496 SCCs were observed. Among men, increased risks of AC and SCC were observed among waiters (SIR = 2.58, 95% CI 1.41-4.32 and SIR = 3.22, 95% CI 2.30-4.38 for AC and SCC, respectively), cooks and stewards (1.72, 1.04-2.69 and 2.53, 1.94-3.25), seamen (1.52, 1.16-1.95 and 1.77, 1.53-2.05), food workers (1.51, 1.18-1.90 and 1.21, 1.03-1.42), miscellaneous construction workers (1.24, 1.04-1.48 and 1.39, 1.25-1.54) and drivers (1.16, 1.01-1.33 and 1.23, 1.13-1.34). Decreased risks of AC and SCC were observed among technical workers, physicians, teachers, religious workers and gardeners. The SIR for AC was significantly different from that for SCC in six occupational categories. Among women, increased risks among food workers and waiters and decreased risks among teachers, nurses and assistant nurses were observed for SCC only. In both sexes, increased risks were observed among waiters and food workers, and decreased risks were observed among teachers. This large cohort study indicates that the risk of oesophageal cancer varies by occupation, but not by histological type in most occupational categories.