A case-control study of the relationships among silica exposure, gastric cancer, and esophageal cancer

Background We examined the effect of silica exposure on gastric and esophag eal cancer mortality using a cancer control series in a population setting. Methods Cases and controls were restricted to male subjects and were drawn from death certificates in the Tobi area of Japan. A control group was sele cted from a series of deaths due to colon cancer and cancers of other organ s. The Japanese death certificate system is comprehensive because all death s must be reported to the local office and death certificates are written b y medical doctors. Age and smoking habits adjusted the Mantel-Haenszel odds ratios were estimated. Results For gastric cancer the age-, smoking-adjusted odds ratios were 1.22 (95% CI 0.74-2.01) for colon cancer and the other cancer control for silic a exposure work, and 1.36 (95% CI 0.76-2.43) for silicosis. For esophageal cancel; the age- and smoking-adjusted odds ratios were 1.53 (95% CI 0.59-3. 96) for the cancer control for silica exposure, and 2.33 (95% CI 0.87-6.23) for silicosis, respectively. Conclusions The results suggest that gastric and esophageal cancer were rel ated to silica exposure and silicosis in the study area, although they did not reach a statistically significant level because of the small sample siz e. The estimated odds ratios were higher for esophageal cancer and silicoti c patients. Am. J. Ind. Med. 39:52-57, 2001. (C) 2001 Wiley-Liss, Inc.