Lifetime Exposure to Welding Fumes and Risk of Some Rare Cancers.

We investigated the association between exposure to welding fumes and the risk of biliary tract, male breast, bone, and thymus cancer, as well as cancer of the small intestine, eye melanoma, and mycosis fungoides, among men in a European, multicenter case-control study. From 1995-1997, 644 cases and 1,959 control subjects from 7 countries were studied with respect to information on welding and potential confounders. We linked the welding histories of the participants with a measurement-based exposure matrix to calculate lifetime exposure to welding fumes. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models, conditional on country and 5-year age groups, and adjusted for education and relevant confounders. Regular welding was associated with an increased risk of cancer of the small intestine (OR = 2.30, 95% CI: 1.17, 4.50). Lifetime exposure to welding fumes above the median of exposed controls was associated with an increased risk of cancer of the small intestine (OR = 2.00, 95% CI: 1.07, 3.72) and male breast (OR = 2.07, 95% CI: 1.14, 3.77), and some elevation in risk was apparent for bone cancer (OR = 1.92, 95% CI: 0.85, 4.34) with increasing lifetime exposure to welding fumes. Welding fumes could contribute to an increased risk of some rare cancers.