Article Type: Original Article
Abstract: Introduction: The incidence of esophageal adenocarcinoma has increased among the white Americans and some Europeans, while the rate of squamous-cell carcinoma in high-risk populations, such asAsians,Africans, Latin and blackAmericans, appears to decrease. We wanted to define the risk of esophageal cancer by histology and length of stay among immigrants in Sweden. Method: The nationwide Swedish Family-Cancer Database (2010 version) was used to calculate standardized incidence ratios (SIRs) for esophageal cancer among the first-generation immigrants compared to the native Swedes. SIRs for lung cancer were also calculated as a proxy for smoking prevalence. The patient series covered 5930 male and 1998 female Swedes, and 410 and 198 immigrants. Results: The risk of esophageal cancer was significantly increased in female Finns (SIR=1.66), Britons (3.73) and Southeast Africans (5.26), while Baltic (0.44), former Yugoslavian (0.47), other European (0.58) and other Asian (0.52) men showed a decreased risk. The risk of squamous-cell carcinoma was increased among Finnish (men=1.32, women=1.90) and Iranian women (3.80), while Danish men (1.66) had an increased risk for adenocarcinoma. No trend was observed for the risks in immigrants according to the length of stay. We found no co-variation between the birth regions specific SIRs for  squamous-cell carcinoma and lung cancer except for Finnish men. Conclusion: Early-childhood exposures or preservation of original habits (smoking, alcohol and nutritional deficiencies) might be the main environmental exposures influencing squamous-cell carcinoma risks in some immigrants. The higher risk of adenocarcinoma among Danish men may confirm the role of obesity on adenocarcinoma risk.
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