Expression And Clinical Significance Of P-gp,GST-Ï€ In Digestive Tract Cancers

Objective:To investigate the expression of P-gp, GST-Ï€in digestive tract cancers and evaluate their clinical significance. To provide basis for further study of mechanism of the multidrug resistance in digestive tract cancers and provide help to choose clinical chemotherapeutic schedues.Methods: 81 cases were examined by the immunohistochemical technique. All of them had not been treated by chemotherapy, radio therapy or immunotherapy before surgery. Among them, 11 had suffered esophaeal cancer, 37 had suffered stomache cancer and 33 had suffered colorectal cancer. Another 36 digestive tract mucosa (9 chronic inflammations of esophagus, 15 chronic superficial gastritis, 12 chronic mucositis of colorectal) were as control.Results :The positive rates of P-gp in esophageal mucosa,stomache mucosa and colorectal mucosa of the control group were 22.2%,40.0% and 41.7% respectively. While in digestive tract cancers the positive rates were 72.7% in esophaeal cancer, 75.7% in stomache cancer and 81.8% in colorectal cancer. There was significant difference in positive expression of P-gp between specimens of the control group and digestive tract cancers(P<0.05).The expression of P-gp in digestive tract cancers was obviously higher than that in specimens of the control group. The expression of P-gp was not associated with age, sex, differentiation grade, depth of invasion, lymphnode metastasis,TNM staging and tumor site(P>0.05).The positive rates of GST-Ï€in esophageal mucosa,stomache mucosa and colorectal mucosa of the control group were 11.1%,26.7% and 33.3% respectively. While in digestive tract cancers the positive rates were 54.5% in esophaeal cancer, 62.2% in stomache cancer and 66.7% in colorectal cancer. There was significant difference in positive expression of GST-Ï€between specimens of the control group and digestive tract cancers(P<0.05).The expression of GST-Ï€in digestive tract cancers was obviously higher than that in specimens of the control group. The expression of GST-Ï€was not associated with age, sex, differentiation grade, depth of invasion, lymphnode metastasis, TNM staging and tumor site(P>0.05).Correlation did not exist between the expression of P-gp and GST-Ï€in digestive tract cancers (P> 0.05).Conclusion:The positive rate of P-gp and GST-Ï€in digestive tract cancers could be used as an index for determination of the multidrug resistance but could not be used as an index to evaluate the malignant degree of tumor and prognosis. P-gp and GST-Ï€play different roles in multidrug resistance in digestive tract cancers. Combined determination of P-gp and GST-Ï€ helps to guide the chemotherapy.