The Epidemiological Study On The Environmental Risk Factors Of Gastric Cancer In Xianyou County

【Objective】To obtain the current situation of gastric cancer in Xianyou; To investigate themain environmental impact factors of gastric cancer; To explore their interactionsabout these risk factors.【Methods】1.Aretrospective investigation of death cause was conducted in Xianyou. Theinvestigation method was referred to the third national survey.Disease classificationfollows the ICD-10coding, population data was from the County Public SecurityBureau, the adjusted mortality was according to the2000national census.Obtain thedistribution and trend of gastric cancer by comparing the three distribution andhistorical survey data.2.A case-control study was conducted to118pair patients and controls.Patientsand equivalent matched controls were recruited from the Xianyou Hospital,the two-fold matched controls were recruited from the healthy population in variousvillagesbased on different gastric cancer mortality.All controls were individual-matched tothe case on gender and age(3years). Eligible subjects were personally interviewedusing the same questionnaire. Univariate and multivariate logistic regression wereused to identify the risk factors of gastric cancer and to estimate the odd ratios (ORs)and95%confidence intervals (95%CIs).3.Application ofpropensityscoreanalysisto assesslogisticregression; randomforest, classification trees were used to get the relative importance factors and explorethe interactions about these risk factors. Logistic regressionanalysis and theAndersson EXCELtables were used to analysis the quantitative interaction. 【Results】1.1176people died of gastric cancer, its crude mortality is54.14/106, thestandardized mortality was49.47/106.male gastric cancer crude mortality was73.93/106,and its mortality was69.26/106, whilefemalegastric cancer crude mortalitywas32.75/106withstandardized mortality28.81/106.gastric cancermortality inmenwas2.44times higher than it in women.gastric cancer was the first leading death causeaccounting for32.79%of malignant tumors.Gastric cancer mortality in Xianyou wassignificantly higher than it Average level in Fujian Province(24.62/106)in2009.2.Comparedwith the firstdeath inquest(19731975),the mortality rateofcancerhad increased from181.93/106to154.40/106, with anincreaseby17.83%.Gastriccan-cer crude mortality had increased from54.14/106to32.79/106million, with an increaseby65.11%; its standardizedmortality ratedroppedfrom29.31/106to37.91/106,with a decrease by22.55%.Xianyougastric cancermortalitywas sig-nificantly higher thanthe surrounding counties, but wasapproximatelyequal to Hanjiang District, Putian City.3.There are obviousdifferences about gastric cancer mortalityamongdifferenttownships, with crudemortality rate98.87/106(standardizedmortalityrate95.40/106)in the high area,contrast to29.19/106(standardized mortality26.39/106)inlow area. Gastric cancermortality indifferentregionswere related to differentterrains,Gastric cancerstandardizedmortality in mountains were83.97/106,50.40/106inhilly,and26.39/10in coast, gastric cancer mortality decliningas altitudedeclining.4.Xianyougastric cancersurvivalwas poor,median survival time was485days.Gastric cancer1-year、2-years、3-year survival rateswere0.5396,0.1867,0.0853respectively. Surgicaltreatment,as anindependentprognosticfactorsof gastric cancer couldimprove the prognosisof gastriccancer.5.The risk factors of gastric cancer in Xianyou including:eating fast (OR=2.53，95%CI:1.28-5.00),often do not eat breakfast (OR=4.35,95%CI:2.89-8.27), taste salty(OR=3.46,95%CI:2.23-5.35),dry and hard diet (OR=11.13,95%CI:4.60-26.94),bingeeating(OR=3.62,95%CI:2.16-6.10),pickled vegetables(OR=2.65,95%CI:1.52-4.62), c-hronicatrophic gastritis (OR=6.18,95%CI:2.51-15.21),family history of cancer(OR=2.77,95%CI:1.75-4.36),first-degree relatives of gastric cancer(OR=3.06,95%CI:1.65-5.66),A-type behavior (OR=9.62,95%CI:3.93-23.53),C-type character (OR=3.06,95CI:1.91-4.90);protection of gastric cancer factors including:garlic (OR=0.11,95%CI:0.06-0.22),onion(OR=0.11,95%CI:0.04-0.15),kelp seaweed(OR=0.55,95%CI:0.35-0.84),tea(OR=0.29,95%CI:0.13-0.64).Helicobacter pylori antibody positive rate in gastric cancer、hospital controls、healthy crowd controls were34.41%、39.81%、48.94%, respectively.6.Logistic regression are consistent with the propensity score; random forestanalysis showed that dry and hard diet was the most important factoraffectingthe incidenceofgastric cancer(MDG=16.6341);classification treeanalysis suggests thatType A behavior, dry and hard diet,over salt diet,overeatingmay haveinteractionsbetween, butthe quantitativeinteractionanalysisdid not findan interactionbetweenthese risk factors.[Conclusion]1.Xianyou has a high incidence of gastric cancer,gastric cancer is the first lead-ing cause of death.Gastric cancer crude mortality rate has rised while its standardizedmortalityrate has declined during40years.2.There are obviousregional differencesin gastric cancermortality rate in Xianyoudifferenttowns, mountains’ sgastric cancer mortalityis high.3.Bad eating habits,tastessaltyandpickles, history of gastrointestinaldiseases andfamily history of cancer, psychological factorsmay be risk factorsof gastric cancerXianyou; teaandonion and garlic, kelpseaweedintakemay beprotective factorsof gastric cancer.4. An interaction may be existed among type A behavior, dry and hard diet,over salt diet and overeating.