[The expression of glutathione S-transferase pi in human ovarian cancer as an indicator of resistance to chemotherapy].

OBJECTIVE: To study the relationship between the expression of glutathione S-transferase pi (GST-pi) in cancer tissue and the chemoresistance in patients with ovarian carcinoma. METHODS: The expression of GST-pi in 53 cases of ovarian cancer, 20 ovarian benign tumors and 17 normal controls was determined by using immunohistochemical SP method and the results were studied in correlation with some clinical and pathological data. RESULTS: (1) Positive expression with GST-pi was demonstrated in 60.4% of malignant and 10.0% of benign ovarian tumors while the expression was negative in normal controls. (2) No significant difference for the expressions was shown in relation to the histopathology, the clinical staging and the size of residual tumors after cytoreductive surgery. (3) The positive rate of the expression was 47.2% (17/36) for the initially treated patients while those with tumor recurrence had a positive rate of 88.2% (15/17). (4) GST-pi positive cases showed less response rate of 37.5% (12/32) to chemotherapy as compared with that of 76.2%(16/21) for GST-pi negative cases. (5) The survival period of the patients with GST-pi positive expression was shorter than that of those with GST-pi negative expression. CONCLUSION: The expression of GST-pi in patients with ovarian carcinoma in closely related to the chemosensitivities clinically. Determinations of the GST-pi are useful for predicting the chemosensitivities and the prognosis of the disease.