Establish Gastric Cancer Scoring Models Of High-risk Population And Study The Opportunistic Screening Method Of Gastric Cancer

BACKGROUND AND AIMS Gastric cancer is a higher incidence andmortality malignant tumor in the world. Compared with adanced gastric cancer,early gastric cancer has a very high therapeutic value and very good therapeuticeffect. The census of gastric cancer and regular follow-up precancerous disease ofpatients are an important means to detect early gastric cancer,but it is difficult tocarry out in our country, which is a backward areas in culture and economic andhave so many people.Opportanistic screcning is a kind of screening based onclinical screening, spending less, do not need extra staff, can be perennial, andpatient compliance is far better than the crowd screening, so are more likely toachieve.But the establishment of screening object,the choice of screeningmethods and the monitoring of high-risk groups have not yet been satisfactorilyresolved.Preliminary studies have shown that in the Ningxia region the gastriccancer risk factors include family history of gastric cancer, pickled food, Jiaowater or well water, age, gender and the histroy of gastric desease,while intakingfresh vegetables and fruits are the protective factors of gastric cancer. Inaddition,The study found that the serum pepsinogen level and the gastricmucosal lesions the degree is closely related, and can identify gastric cancerrisk factors-atrophic gastritis, can be used as the detection method of massscreening for gastric cancer risk.The study of cancer antibodies MG7consider thatMG7-Ag and gastric cancer has a good correlation, it is possible improve the detection rate of early gastric cancer by close monitoring the people who isMG7-Ag-positive atrophic gastritis, intestinal metaplasia and dysplasia. Study thehigh risks of gastric cancer risk factor by the non-conditional Logistic regressionanalysis to establish scoring models, and established low-risk groups and high-riskgroups. Combined with the results of MG7-Ag expression and endoscopy andhistopathological examination after one year follow-up,to explore inopportunistic screening in the clinical out-patient work the object established ofscreening, the choice of screening methods, the monitoring of high-riskgroups, to improve the purpose of early diagnosis of gastric cancer.METHODS Collect the relevant information of383volunteers through thequestionnaire such as age, gender, type of drinking water, gastric cancer familyhistory, fresh vegetables and pickles food frequency.All patients underwentendoscopy to confirm the diagnosis and gather specimens from biopsy tissue andserological samples. Double antibody sandwich enzyme-linked immunosorbentassay (ELISA) determinate the levels serum pepsinogen I and Ⅱof thevolunteers, Histologic improvement by Giemsa dyeing and immunohistochemicalmethod to detect the HP and MG7expression in the all kind gastric mucosaltissues. A case-control study, the questionnaire and Hp, the PG test results tonon-conditional logistic regression analysis, Conclude that the risk factors ofgastric cancer and their return ratio β, Calculate the multiples of other independentvariables β value compared to the smallest β value base, and that is eachindependent variable corresponding scores. Through this way, appropriate toquantify gastric cancer related factors to establish the scoring models. Score of384patients by receiver operating characteristic (reeeiveroperating characteristie,RoC) curve to determine the score cutoff value for diagnosis of gastric cancer, andaccordingly divided into low-risk, high-risk groups. Combination of MG7-Ag parallel test results on some non-gastric cancer patients after one year follow-upendoscopy and analysis of results.RESULTS1. Single factor analysis show gastric cancer influencing factorsare: age, sex, drinking water and gastric cancer family history, Hp infection, thePG level, pickled products. By Logistic multivariate regression analysis, the sixstatistically significant factors were: gender (OR=2.250,95%CI1.185~4.275);drinking water (OR=2.425,95%CI,1.356~4.338); Hp infection (OR=2.184,95%CI1.054~4.523); family history (OR=3.231,95%CI1.672~6.242);PG level (OR=5.768,95%CI3.207~10.374), age (OR=4.314,95%CI,2.375~7.838).Age≧55, male, drinking pit water or well water, a gastric cancer familyhistory of HP infection, serum PG I≦43.6g/L and the PG Ⅰ/PG II≦2.1level are the factors affecting the gastric cancer。2.383volunteers HP infection positive rate was72.8%. Compared with superficialgastritis, the positive rate of Hp infection of peptic ulcer and gastric cancer havesignificant difference.(P<0.01).Compared peptic ulcer with gastric cancergroup,and compared superficial gastritis with atrophic gastritis, Helicobacterpylori infection differences no significant(P>0.05).3. By ELSIA method to detect every kind of chronic gastric disease the levels ofserum PG I and PG Ⅱ show:（1）compared with superficial gastritis, the serum ofPGI and PG I/PG Ⅱ in atrophic gastritis and gastric cancer patients drop, PGI/PG Ⅱ in peptic ulcers group drop; the serum of PGI and PG Ⅱ in peptic ulcersincrease,whith with significant difference (P <0.05or P <0.01); Compared withgastritis cancer group, atrophic gastritis group PG I/PG Ⅱ ratio, also hassignificant difference (P <0.01).(2)Develope the receiver operating characteristic(ROC) curves to determiner the cutoff of PGI and PGI/PG Ⅱ of the gastric cance:PGI cutoff is43.6IU/L, the sensitivity of0.528, the specific degrees for0.778;The ratio of PGI/PGII cutoff is2.1, the sensitivity of0.577, the specific degrees for0.848.(3)The PGI, the PGI/PG II paralleled, sensitivity is0.717, specificity is0.754, when serie, sensitivity is0.90, specificity is0.342.4. Establish high-risk scoring models of gastric cancer in non-conditional logisticregression analysis:Y=A,×age sex to+30×to+30×drinking water to+30×Hp infection to gastriccancer family history of+50×+B x the PG level (when35<age <=45A=20;45<age≦55, A=40;55<age≦65when A,=70; age>65, A,=80; when the PGⅠ≦43.6g/L and the PG Ⅰ,/the PG II>2.1, B,=10; the PG Ⅰ>43.6g/L,and PG I/PG II≦2.1, B=30; PG Ⅰ≦43.6g/L, and the PG Ⅰ/PG II≦2.1,B=80). Develope the receiver operating characteristic (ROC) curves todeterminer the cutoff score of gastric cancer high-risk groups identified as≥155points, the area under the curve is0.875, the sensitivity is0.879and thespecificity was.715, the Youden index of0.594。5. Using immunohistochemical method to test MG7-Ag in the gastric mucosal of217volunteers, the results showed that: The MG7-Ag positive expression rate ofgastric cancer is93.9%,superficial gastritis is15%, atrophic gastritis withintestinal metaplasia is81.5%and dysplasia is83.7%.Compared with superficialgastritis group and peptic ulcers, atrophic gastritis with intestinal metaplasia,dysplasia group, have a statistics difference (p <0.01or p <0.05).Compared withstomach cancer group, superficial gastritis group, atrophic gastritis with intestinalmetaplasia, dysplasia group, have a statistics difference (p <0.01or p <0.05).6. MG7-Ag expression rate in atrophic gastritis with intestinal metaplasia group,dysplasia group and stomach cancer group are higher, high-risk group MG7-Agexpression rate is higher than the corresponding low-risk groups, the differencewas statistically significant (P <0.05).And MG7-Ag expression rate in superficial gastritis group and peptic ulcers group are lower, high-risk group MG7-Agexpression rate are same to the corresponding low-risk groups, the differencewas not statistically significant (P <0.05).7. One year later we have followed-up to the non-gastric cancer patients to dogastroscope and pathology inspection again,complete26cases,3cases weredetected early gastric cancer,1case was detected stomach Angle lesions, andpathological diagnosis is the high-level neoplasia, the four patients are MG7-Agpositive expression of high-risk groups of patients. The four patients are theMG7-Ag-positive expression high-risk group patients.3cases of early cancerpatients have line of surgical treatment,1cases of the gastric fundus cancer,1case of gastric cardia gastric cancer,1case of distal gastric cancer,andpathological diagnosis is high differentiated adenocarcinoma, middle-highdifferentiated adenocarcinoma and low differentiated adenocarcinoma in turn.After surgery, pathological tumor stage are all T1N0M0,, early gastric cancerdetection rate of15.8%.CONCLUSION1. Age≧55, male, drinking pit water or well water, agastric cancer family history of HP infection, serum PG I≦43.6g/L and the PGⅠ/PG II≦2.1level are gastric cancer risk factors.2. Serum pepsin the original level and the extent of the gastric mucosa lesions isclosely related to, PGⅠ≦43.6g/L, PG Ⅰ/PG Ⅱ≦2.1parallel is the bestdefine value detection stomach cancer.3. Using statistical methods to establish high-risk scoring models to determine thescore≧155is divided into high risk gastric cancer screening cutoff value, hascost-effective and high sensitivity and specificity.4. MG7-Ag and gastric cancer development has the good correlation, it hashigh specificity to diagnosis gastric cancer. MG7-Ag in gastric cancer before the disease dynamic follow-up has important application value, atrophic gastritis,intestinal metaplasia and dysplasia close monitoring may improve the detectionrate of early gastric cancer.5. Suggested high-risk gastric cancer pepole opportunistic screening and follow-upplan:1) The target population: the upper gastrointestinal symptoms patients,make the risk factors questionnaire (age, sex, stomach family history, long-termdrinking water type) and Hp detection, PG detection.2) According theestablished gastric cancer risk scoring models to the questionnaire survey and Hpand PG inspection results make score,scoring≧155as frequency stomachhigh-risk groups, suggest line gastroscope inspection and every1-2yearsfollow-up endoscopy, according to the situation of gastric mucosal tissuepathology biopsies and MG7detection.3) mucosal pathologic biopsy suggests thepatient of atypical hyperplasia and or MG7testing positive expression, asgastric cancer sicken very high-risk groups, the proposal closely followed up,every six months to one year for a gastroscope inspection.