The expression of MRP, GST-pi, Topo IIalpha and COX-2 in epithelial ovarian cancer and its relationship to drug resistance and prognosis

Abstract

To study the expression of MRP, GST-pi, Topo IIalpha and COX-2 in epithelial ovarian cancer (EOC) and its relationship to drug resistance and prognosis. Immunohistochemical method was used to study the expression of MRP, GST-pi, Topo IIalpha and COX-2 in 60 cases of epithelial ovarian cancer who were treated in PUMC Hospital from 2000 to 2004. The mean age of all patients was 51.2 years old. The histological types were 35 cases of serous adenocarcinoma, 2 cases of mucinous adenocarcinoma, 11 cases of clear cell carcinoma, 4 cases of transitional cell carcinoma and 8 cases of endometrioid carcinoma. Statistical analysis was done to determine its relationships to drug resistance and prognosis. The positive expression rate of MRP, GST-pi, Topo IIalpha and COX-2 in EOC was 26.7%, 93.3%, 61.7% and 78.3% respectively. The positive expression rate of MRP was significantly higher in clear cell carcinoma than that in non-clear cell carcinoma (54.5% vs 20.4%, P < 0.05); The expression of Topo IIalpha in advanced stage of EOC was significantly lower than that in early stage cases (56.6% vs 78.6%, P < 0.05). Positive expression of MRP, negative expression of Topo IIalpha, strong positive expression of GST-pi and COX-2 were seen as four risk factors for recurrence, drug-resistance and poor prognosis. More cases of recurrent group and drug-resistant group had 2 or more risk factors. The three-year survival rate of patients with 2 or more risk factors and patients with less than 2 risk factor are 69.9% and 91.7% respectively (P > 0.05). There are moderate or high expression of MRP, GST-pi, Topo IIalpha and COX-2 in epithelial ovarian cancer. Having 2 or more risk factors may be seen as a vital indicator to predict drug-resistance and recurrence in patients of epithelial ovarian cancer.