[Expression of glutathione S-transferase-pi in operative specimens as marker of chemoresistance in patients with ovarian cancer].

OBJECTIVE: To study the relationship between the expression of glutathione S-transferase-pi (GST-pi) in operative specimens and chemoresistance in patients with ovarian cancer. METHODS: The expression of GST-pi in 87 epithelial ovarian cancer tissues and 30 normal ovarian epithelial tissues was determined with labelled streptavidin biotin method (LSAB). All the patients had not received chemotherapy before operation. We used Chi-Square and Cox-Mantel test to analyze the relativity between the expression of GST-pi and clinical pathological data, chemotherapeutic response, prognosis in patients with ovarian cancer. RESULTS: (1) 59 (67.8%) of 87 ovarian cancer tissue were demonstrated to be positive expression with GST-pi, but all 30 normal ovarian epithelial tissue were negative. (2) There was no direct correlation between the expression of GST-pi and clinical pathological data. (3) 43 (43/59) of GST-pi positive cases were chemoresistant, while only 3 (3/28) of GST-pi negative ones were chemoresistant. (4) The difference in the chemotherapeutic response between the two groups was obviously significant (P < 0.005). The survival period of the patients with GST-pi positive expression was also obviously shorter than that of those with GST-pi negative expression (P = 0.004). CONCLUSION: These results strongly suggest that GST-pi expression in epithelial ovarian cancer tissues is closely related to chemoresistance clinically and it may be served as a useful marker to predict the prognosis of patients.