The Association Between The Environmental Factors And The High Risk Of Esophageal Cancer Among The Immigrants In Zhongxiang

Objective: Esopahgeal cancer(EC) is characterized by distinctly higher incidence in certain geographical locations. This regional distribution suggests that the environmental and genetic factors might play an important role in the pathogenesis of esophageal cancer . About 40,000 inhabitants who had lived in this high risk area of Xichuan County, Henan Province emigrated to a low ESCC risk area, Caihu Town of Hubei Province, during 1964~1965 year because of the construction of a dam over Han River. In the previous study, we found that the mortality rate of esophageal cancer of migrants was 9–folds higher than that of the host population. In an attempt to better understand the etiology of esophageal cancer, we conducted a study in these migrants to expolre the risk environmental factors in the carcinogenesis of EC.Method: There migrant 572 familes and 395 host families, and 2690 migrants and1919 host residents were recruited in this study. 957 junior school students were selected randomly and trained as investigator to conduct 1) questionnaire survey to their family about the family living condition including housing, cooking energy, ventilation, family diet habit et al; 2) questionnarie survey to the family member about the lifestyle including smoking, alcohol drinking, physical excerise, diet habit et. al. The data set was established with EpiData3.1 software, SAS 8.1 was used to do the statistical analysis. Chi-square was used to analyse the categorical data, and T-test was used to analyse the numerical data. The significance was established at P<0.05 with a two-side test.Result: The result showed that the economic situation of immigrants was worse than that of local residents, which reflected in low cash income, poor housing conditions (P <0.05). The migrant had more seriou problems in indoor air quality, which reflected by the high proportion on no chimney, no dedicated room for cooking, non-clean energy for cooking. In the diet habit, the migrants have higher prevelance on the hot food or drinking, less fresh egg intaking, taking more wheat as staple food, more consumption of pickles, improper food storage methods, high intake of the salt (P <0.05), a higher proportion of immigrants to choose water instead of tap water as drinking water sources. Personal living habits: the immigrants in the proportion of alcohol drinking(P <0.05),there is no significant difference on smoking ratr (P >0.05). Immigrant families have a family history of esophageal cancer was significantly higher than that of local residents (P<0.01). This study also found the significant differences among the second-generation immigrants, first generation of immigrants and local residents, the diet pattern of second-generation gradually towards that of the local residents.Conclusion: The economic situation,indoor air pollution, wheat as staple food, hot food or drinking , improper food storage methods , unsanitary drinking water, poor eating habits, inadequate nutrition intaking might be risk factor for high risk factor for migrants Although these environmental factors in the immigrants and local residents of the difference was significant, but whether these risk factors can explain the higher incidence of esophageal cancer among migrants need further study.