The evidence for an association between occupational
asbestos exposure and esophageal, gastric and
colorectal cancer is limited. We studied this association specifically addressing risk differences between relatively low and high exposure, risk associated with
cancer subtypes, the influence of potential confounders and the interaction between
asbestos and smoking in relation to
cancer risk. Using the Netherlands Cohort Study (n = 58,279 men, aged 55-69 years at baseline),
asbestos exposure was estimated by linkage to a job-exposure matrix. After 17.3 years of follow-up, 187 esophageal, 486 gastric and 1,724
colorectal cancer cases were available for analysis. The models adjusted for age and family history of
cancer showed that mainly (prolonged) exposure to high levels of
asbestos was statistically significantly associated with risk of esophageal
adenocarcinoma (EAC), total and distal
colon cancer and
rectal cancer. For overall
gastric cancer and gastric non-cardia
adenocarcinoma (GNCA), also exposure to lower levels of
asbestos was associated. Additional adjustment for lifestyle confounders, especially smoking status, yielded non-significant associations with overall
gastric cancer and GNCA in the multivariable-adjusted model, except for the prolonged highly exposed subjects (tertile 3 vs. never: HR 2.67, 95% CI: 1.11-6.44 and HR 3.35, 95% CI: 1.33-8.44, respectively). No statistically significant additive or multiplicative interaction between
asbestos and smoking was observed for any of the studied
cancers. This prospective population-based study showed that (prolonged) high
asbestos exposure was associated with overall
gastric cancer, EAC, GNCA, total and distal
colon cancer and
rectal cancer.