Immunohistochemical analysis of glutathione S-transferase mu expression in ovarian tumors.
OBJECTIVE: To explore the association between Glutathione S-transferase (GST) -mu expression and clinicopathologic features in ovarian tumors. STUDY DESIGN: Immunohistochemical study was made to investigate GST-mu expression in diverse ovarian tumors. RESULTS: All 75 ovarian tumors expressed GST-mu. There was no significant association between GST-mu immunopositivity and clinicopathological features. In serous cystadenocarcinoma, however, patients with weak GST-mu expression survived longer than those with moderate or strong GST-mu expression. Three of the 8 tumors that had expressed weak GST-mu initially increased GST-mu expression after chemotherapy. CONCLUSION: GST-mu expression is common in ovarian tumors and malignant tumors expressed more GST-mu than benign tumors. GST-mu might play a major role in the development of drug resistance in certain ovarian tumors and could be a useful marker of natural resistance and their future outcome.