The Association Between Overweight,Obesity And Biliary Tract Cancers(BTC):A Meta-Analysis

Background:Cholangiocarcinoma is a relatively rare malignant tumor of the digestive system,including gallbladder carcinoma,cholangiocarcinoma and ampullary carcinoma.In recent years,it has been reported that the morbidity and mortality of biliary cancer are on the rise,especially in South America and Asia.Due to the concealment of bile duct cancer and the lack of typical symptoms in the early stage.The diagnosis,treatment and prognosis of most patients with bile duct cancer are very poor because of the lack of early diagnosis methods.Biliary tract cancer is a disease caused by multiple pathogenic factors.The existing research data of internal and foreign shows that cholelithiasis,hepatitis B,hepatitis C infection,clonorchiasis infection,ulcerative colitis are the risk factors of biliary tract cancer.However,The etiology of cholangiocarcinoma has not been fully explained clearly.Since there is no effective general investigation for biliary cancer,it is particularly important to identify risk factors.Recent studies have shown that obesity and overweight lead to a significant increase in the risk of biliary cancer,but the results are not the same.In addition,whether the association between overweight and biliary cancer is affected by gender and regional differences remains controversial.Objective:This study analyzed existing studies to further investigate the association between overweight and the risk of biliary cancer,and to evaluate whether gender and regional differences can be used as related factors for risk of the biliary cancer.In this study,in order to explore the relationship between overweight and bile duct cancer,we searched comprehensively internal and foreign literature about overweight and bile duct cancer.Methods:We collected published literature from database establishment to January 2019 from PubMed,Embase and Chinese databases,in order to explore the relationship between overweight,obesity and the risk of gallbladder cancer and extrahepaticcholangiocarcinoma.To define the inclusion and exclusion criteria,and to screen the research of pre-inclusion analysis,to evaluate the quality of the inclusion research,and to extract the effective information of the full text.The data analysis and system evaluation are carried out by using the STATA12.0 software developed by Stata Company.Including heterogeneity test to evaluate the difference between pre-included studies,combined total effect to clarify the relationship between BMI and bile duct cancer risk,subgroup analysis to explain the main sources of heterogeneity and further explore the impact of important factors on the overall results.Sensitivity analysis and publication bias analysis were used to investigate the stability and reliability of the results.Results:All 11 cohort studies were included in this study,including 4 European studies,4American studies and 3 Asian studies.This study included 9 studies related to the occurrence of gallbladder carcinoma and 6 studies related to the occurrence of extrahepatic cholangiocarcinoma.All studies were evaluated with NOS quality score scale.the results showed that the quality score was between 6 and 9,all of studies met the criteria of Meta analysis.According to the classification of cholangiocarcinoma,independent Meta analysis was performed for gallbladder carcinoma and extrahepatic cholangiocarcinoma.The RR values of overweight and gallbladder carcinoma,obesity and gallbladder carcinoma,overweight and extrahepatic cholangiocarcinoma,obesity and extrahepatic cholangiocarcinoma were 1.08,1.63,1.21 and 1.74 respectively,all values are statistically significant.The results of subgroup analysis according to sex showed that the risk of gallbladder cancer in the obese women was significantly higher than that in men.The results of subgroup analysis according to the region showed that the risk of gallbladder cancer in Europe and the United States was higher than that in Asia in the obese population,but the risk group of cholangiocarcinoma in Asia was higher than that in Europe and the United States in the obese population.Conclusion:The overweight is a risk factor for biliary cancer,which indicates that maintaining a healthy weight can prevent the occurrence of biliary cancer to a certain extent.Compared with obese men,the obesity was more significantly associated with gallbladder cancer in obese women.