Occupational exposure and smoking adjusted risk of bladder cancer. Population based cohort studies in the Nordic countries.
Session type: Poster / e-Poster / Silent Theatre session
Occupational exposure has been identified as the most important risk factor for bladder cancer second to smoking. The objective of this study was to observe the occupational variation in risk of bladder cancer that is not attributable to smoking.
In the Nordic Occupational Cancer (NOCCA) study, 111,458 cases of bladder cancer cases were observed among men in Denmark, Finland, Iceland, Norway and Sweden during 1961-2005. In this study we used confirmatory factor analysis models for simultaneous analysis of bladder cancer related to tobacco. The unobserved pattern of smoking habits was considered latent common factors. Results was used to compute expected numbers of cancer from reference rates, adjusted for tobacco smoking. Crude and smoking-adjusted SIRs for bladder cancer with 95% confidence intervals (CI) were calculated for the 54 occupational categories as defined in NOCCA.
The smoking-adjusted SIR for virtually all of the occupations was closer to 1.00 than the unadjusted SIR. The highest unadjusted risk among Nordic men was observed among chimney sweeps (SIR 1.49, 95% CI 1.21-1.80), waiters (1.42, 1.25-1.61), hairdressers (1.30, 1.17-1.45), assistant nurses (1.28, 1.09-1.50), seamen (1.22, 1.16-1.28), plumbers (1.20, 1.13-1.28), tobacco workers (1.18, 0.79-1.70), printers (1.18, 1.11-1.26).The risk was closer to 1.00 for almost all the occupations after smoking adjustment. Chimney sweeps (1.21, 0.99-1.47), waiters (1.06, 0.93-1.20), hairdressers (1.10, 0.99-1.22), assistant nurses (1.23, 1.05-1.44), seamen (1.02, 0.97-1.07), plumbers (1.03, 0.97-1.10), tobacco workers (0.98, 0.66-1.40) and printers (1.04, 0.98-1.11). The risk was highest in Denmark while the lowest in Finland.
Smoking is a strong risk factor for bladder cancer but there are also other risk-increasing factors in some occupations signifying the risk due to occupation. The occupational variation in risk of bladder cancer is small when adjusted for smoking.