OBJECTIVE Ci-xian County is located in the north of Chinaand is a high-risk area for esophageal cancer(EC).In 2004,theincidence rate of EC in the county was 127/100,000 and 93/100,000in the male and female population,respectively,and that ofgastric cancer(GC)was 72/100,000 and 36/100,000.Since 2001 acohort screening,supported by a special national fund,utilizingendoscopic examination with iodine staining for the targetpopulation at the age ranging from 40 to 69 years was carried out,so as to reduce the incidence and mortality rates in the high-riskareas of EC.METHODS In October 2001,4 townships in the Ci-xian County,Hebei,China were selected,with 22,016 cases in the interventiongroup(IVG)and 33,410 in the control group(CG).The totalpopulation coverage reached 55,000.There were 3257 males and3339 females in the IVG with the age ranging from 40 to 69 years,and 4299 males and 4430 females in the CG with the same rangeof the age.Endoscopic screening with iodine staining was used inthe IVG,with a screening rate of 53.2%.During the screening byendoscopic examination,97 cases were found to have esophagealsquamous epithelium,carcinoma-in-situ at the cardiac glandularepithelium or intra-mucosal carcinoma.Additionally,102cases were identified to have severe atypical hyperplasia in theesophagus and gastric cardia.The natural incidence rate of cancerand the mortality were observed in the CG.The ICD-0 version wasused in the tumor incidence and death registration coding.Duringa period from June to September 2008,based on the information ofthe tumor registration database of the incidence and mortality inthe Ci-xian County,the cohort groups were studied and followed.RESULTS There were 133 patients with untreatable EC and48 with GC in the IVG,while there were 259 and 37 patients inthe CG who died of esophageal and gastric cancer,respectively.The relative risk(RR)of death was 0.76 in the male patients withEC,95%CI(0.59-0.98),P=0.038,and in the female patients theRR was 0.51,95%CI(0.35-0.75),P=0.000.The RR of death in theGC patients was 2.45,(1.40-4.29)in the male,P=0.01,and 0.99,(0.47-1.99),in the female cases,P=0.906.CONCLUSION Six years after a cohort screening of a largepopulation by endoscopic examination with iodine staining inareas at high risk for EC,the death risk in the male and femalepatients with EC has decreased compared with that in the controlgroup.The difference between the 2 groups was statisticallysignificant.However,no protective method used to decrease thedeath risk in GC patients has been found during this period ofendoscopic screening.
