Occupational exposure to electromagnetic fields and sex-differential risk of uveal melanoma.

OBJECTIVES: The association between occupational exposure to electromagnetic fields (EMF) and the risk of uveal melanoma was investigated in a case-control study in nine European countries. METHODS: Incident cases of uveal melanoma and population as well as hospital controls were included and frequency matched by country, 5-year birth cohort and sex. Subjects were asked whether they had worked close to high-voltage electrical transmission installations, computer screens and various electrical machines, or in complex electrical environments. Measurements of two Scandinavian job-exposure matrices were applied to estimate lifelong cumulative EMF exposure. Unconditional logistic regression analyses, stratified by sex and eye colour were calculated, adjusting for several potential confounders. RESULTS: 293 patients with uveal melanoma and 3198 control subjects were interviewed. Women exposed to electrical transmission installations showed elevated risks (OR 5.81, 95% CI 1.72 to 19.66). Positive associations with exposure to control rooms were seen among men and women, but most risk increases were restricted to subjects with dark iris colour. Application of published EMF measurements revealed stronger risk increases among women compared to men. Again, elevated risks were restricted to subjects with dark eye colour. CONCLUSION: Although based on a low prevalence of exposure to potential occupational sources of EMF, our data indicate that exposed dark-eyed women may be at particular risk for uveal melanoma.

Hormonal exposures and the risk of uveal melanoma.

OBJECTIVES: Several studies suggest that hormonal mechanisms may be associated with the development of uveal melanoma. Therefore, the association between the risk of uveal melanoma and exposure to hormonal exposures was investigated in a case-control study from nine European countries. METHODS: Incident cases of uveal melanoma were frequency-matched to population and hospital controls by country, age, and sex. Female subjects were asked about their reproductive history, use of menopausal hormone replacement therapy and oral contraceptives. Among men, occupational handling of oils while working with transformers or capacitors which contain polychlorinated biphenyls (PCB) was solicited. Unconditional logistic regression analyses were calculated, adjusting for several potential confounders. Analyses were stratified by sex. RESULTS: Two hundred and ninety-three cases (165 men, 128 women) and 3,198 control subjects (2,121 men, 1,077 women) were interviewed. Among women, no associations were observed with hormonal status variables, intake of hormonal therapy or intake of oral contraceptives. Men showed an increased risk with occupational exposure to transformer/capacitor oils (OR = 2.74; Bonferroni-corrected 99.3% CI 1.07-7.02). However, these results were based on few exposed subjects only. CONCLUSION: The results of this study do not support the hypothesis of a hormonal influence in the carcinogenesis of uveal melanoma. Our finding of a potentially increased risk with PCB-containing oils requires further research.