title: Diagnosis of gastric malignancy using gastric juice alpha1-antitrypsin.
abstract: No accurate, inexpensive, and noninvasive test for gastric cancer screening is currently available. Our recent study identified alpha1-antitrypsin as a potential biomarker of gastric cancer in gastric juice. The aim of this study was to develop a novel noninvasive modality for detecting gastric cancer by measurement of alpha1-antitrypsin concentration in gastric juice. The work consisted of two parts: (a) investigating the differences in gastric juice alpha1-antitrypsin concentrations between gastric cancer patients and controls, and (b) screening gastric cancer using string test to obtain gastric juice followed by immunoassay for alpha1-antitrypsin concentration. The data showed that gastric juice alpha1-antitrypsin concentration was markedly higher in gastric cancer patients than in healthy subjects, gastric ulcer patients, and duodenal ulcer patients (all P < 0.001). The area under the receiver operating characteristic curve for identifying gastric cancer cases was 0.96 (95% confidence interval, 0.93-0.99; P < 0.001). The sensitivity and specificity of gastric juice alpha1-antitrypsin concentration were 96% and 92%, respectively. Gastric juice alpha1-antitrypsin assay through string test was validated in 93 consecutive patients for gastric cancer screening. The sensitivity and specificity of gastric juice alpha1-antitrypsin string test at 85% accuracy were 74% and 88%, respectively. The area under the receiver operating characteristic curve for identifying gastric cancer was 0.84. In conclusion, gastric juice alpha1-antitrypsin concentration in gastric cancer patients markedly exceeds those in healthy subjects and patients with benign gastrointestinal diseases. A noninvasive alpha1-antitrypsin string test may serve as a new screening tool for identifying gastric cancer patients.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Veterans General Hospital and National Yang-Ming University, Kaohsiung, Taiwan.
authors.forename: Ping-I
authors.initials: PI
authors.lastname: Hsu
authors.forename: Chung-Hsuan
authors.initials: CH
authors.lastname: Chen
authors.forename: Michael
authors.initials: M
authors.lastname: Hsiao
authors.forename: Deng-Chyang
authors.initials: DC
authors.lastname: Wu
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Lin
authors.forename: Kwok-Hung
authors.initials: KH
authors.lastname: Lai
authors.forename: Pei-Jung
authors.initials: PJ
authors.lastname: Lu
mesh_terms: D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005750:Gastric Juice / Q000737:chemistry*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000175:diagnosis*; D000515:alpha 1-Antitrypsin / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; C043392:SERPINA1 protein, human; D000515:alpha 1-Antitrypsin