ABSTRACT
Objective To explore a highly sensitive and highly specific method to detect the serum MG7 antigen (Ag) level for early gastric cancer diagnosis.Methods The serum MG7-Ag level was detected by enzyme-linked immunosorbent assay (ELISA) method in 116 preoperative gastric cancer patients,63 postoperative gastric cancer patients,41 patients with precancerous lesion,37 patients with precancerous diseases,50 healthy individuals and 281 patients with other cancers.Meanwhile,the expression of MG7-Ag was also examined with immunohistochemistry in patients with gastric cancer or precancerous lesion.Chi-square test was used for comparing positive rates of the two detection methods.Results The positive rate of MG7-Ag determined by ELISA was 83.6％(97/116) of preoperative gastric cancer patients,45.2％(28/62) of lung cancer patients,45.5％(20/44) of rectal cancer patients,17.6％ (12/68) of colonic cancer patients,14.2％ (6/42) of breast cancer patients,47.6％ (30/63) of postoperative gastric cancer patients,19.5 ％ (8/4 1) of patients with precancerous lesions,5.4 ％ (2/37) of patients with precancerous diseases and 0 of healthy individuals.The sensitivity of ELISA (83.6 ％) was similar with that of immunohistochemistry (94.0％)(P＞0.05).However,the false positive rate of ELISA (12.8 ％) was lower than that of immunohistochemistry (51.3 ％) (x2 =26.491,P＜0.01).There was statistically significant difference in MG7 Ag expression in gastric cancer with different clinical stages (x2=15.564,P＜0.01).Conclusion This ELISA method might be a non-invasive screening method for population with high risk of gastric cancer.
ABSTRACT
Objective To investigate the correlation and significance of cyclooxygenase-2 (COX-2) an d gastric cancer-associated antigen MG7(MG7-Ag) in gastric carcinoma and non- cancerous tissues. Methods Avidin-biotin peroxidase complex immunohistochemical method was adopted to exam ine the expression of COX-2 and MG7-Ag in the gastric mucosa of 100 patients w ith gastric carcinoma. The Helicobacter pylori(H. pylori) infection in gastr ic carcinoma was determined by blue amino toluene stain and modified Giemsa stai n. Results The positive rates of COX-2 and MG7-Ag in gastric carcinoma were 88.0% and 92. 0% respectively. From chronic superficial gastritis, chronic atrophic gastritis, intestinal metaplasia to dysplasia, the expression of COX-2 and MG7-Ag showed a n ascending tendency. Both COX-2 and MG7-Ag were expressed at higher level in cases with lymph nodes or distal organs metastasis than those without (P
ABSTRACT
Recently new tumor marker, MG7-Ag has been introduced for screening of gastric cancer. In this study MG7-Ag and CEA in sera of 50 normal healthy Koreans and 48 patients with gastric cancer group were determined to elucidate the clinical usefulness for gastric cancer screening. Commercial Enzyme Immuno Assay kits were used for analysis of above two markers. Sensitivity of MG7-Ag and CEA in patient group were found to be 43.8% and 41.7%, respectively. When the two markers were used combind, sensitivity increased to 62.5%. The concentration of MG7-Ag in patients (9.2+11.7 U/mL) was five times higher than normal control group (1.81+1.63 U/mL). CEA was 31.2+46.5 ng/mL in patients and 2.24+0.98 ng/mL (MeanSD) in normal control group. From this results, combination assay of MG7-Ag and CEA is more useful in clinical laboratories for screening gastric cancer than using one marker.