Value of P-glycoprotein, glutathione S-transferase pi, c-erbB-2, and p53 as prognostic factors in ovarian carcinomas

Abstract

Purpose: To determine the prognostic value of immunostaining of P-glycoprotein (P-gp), glutathione S-transferase (GST) pi, c-erbB-2, and p53 in patients with advanced-stage ovarian carcinoma.

Patients and methods: Immunostaining of P-gp, GST pi, c-erbB-2, and p53 was performed on 89 primary tumors and 38 residual tumors after chemotherapy (P-gp and GST pi) in patients with advanced ovarian carcinoma treated with platinum- and doxorubicin-containing chemotherapy. The results of immunostaining were related to clinicopathologic prognostic factors, response to chemotherapy, and progression-free survival (PFS) and overall survival.

Results: P-gp and GST pi immunoreactivity were present in 13 (15%) and 79 cases (89%), respectively, and were not associated with any other prognostic factor or PFS or overall survival. C-erbB-2 immunoreactivity was present in 18 cases (20%) and was associated with undifferentiated histiotype (P < .05), but not with PFS or overall survival. p53 immunoreactivity was present in the nuclei of 31 cases (35%) and cytoplasm of nine cases (10%). Nuclear p53 staining was associated with grade III tumors, presence of more than 1-L ascites, and residual tumor after first laparotomy more than 2 cm. Nuclear p53 staining was associated with shorter PFS (relative risk [RR], 3.3; 95% confidence interval [CI], 2.0 to 5.6) and overall survival (RR, 2.6; 95% CI, 1.7 to 3.8). After adjustment for presence of more than 1-L ascites or age more than 50 years, nuclear p53 staining did not retain independent prognostic significance in stage III/IV tumors. The frequency of P-gp staining in residual tumors after chemotherapy (18 of 38 cases) was higher in comparison to untreated tumors (13 of 89 cases) (P < .001). No combination of prognostic parameters was able to predict response to chemotherapy adequately.

Conclusion: Nuclear immunoreactivity of p53 in ovarian carcinomas is associated with shorter PFS and overall survival and determinants of more aggressive tumor growth. The higher frequency of P-gp immunoreactivity in residual tumors after chemotherapy points to induction of P-gp in ovarian carcinomas by doxorubicin-containing combination chemotherapy. The determination of P-gp, GST pi, c-erbB-2, and p53 does not permit more adequate prediction of response to chemotherapy.