IMMUNOPHENOTYPE OF OVARIAN-CANCER AS PREDICTOR OF CLINICAL OUTCOME - EVALUATION AT PRIMARY SURGERY AND 2ND-LOOK PROCEDURE

Objective. This study was undertaken to evaluate whether immunophenoty ping of advanced epithelial ovarian cancer could predict response to i nitial chemotherapy and whether tumor immunophenotype changed after ch emotherapy. Study design. Fifty-four patients with stage III and IV ov arian cancer, treated at the University of Washington Medical Center, had pathology specimens evaluated. A subset of 23 patients also had sp ecimens from a secondary surgery evaluated. Using immunocytochemistry, tumors were immunostained for overexpression of c-erb-B-2, epidermal growth factor receptor (EGFR), p53, and expression of the Ki67-defined antigen (a marker of cellular proliferation), tumor necrosis factor a lpha (TNF alpha), estrogen receptor (ER), progesterone receptor (PR), and P-glycoprotein (P170, a marker of multidrug resistance). Twenty-fo ur patients had a good response to chemotherapy (defined as a negative , or microscopically positive second look), and 30 had a poor response (defined as grossly positive second look or progressive disease). Res ults. Comparison of tumor markers from the initial and the secondary s urgeries revealed that the only significant change was in the Ki67-def ined cell proliferation rate, which showed a marked reduction in those with a good response to chemotherapy (P = 0.002). Comparison of tumor markers at initial surgery between good and poor responders revealed a correlation with p53 expression. Good responders were less likely to have p53 overexpression compared to poor responders, and this result approached significance (P = 0.058). Comparison of tumor markers at se condary surgery revealed a significant reduction in Ki67-defined cell proliferation rate in good responders compared to poor responders (P = 0.01). No significant differences were found between good and poor re sponders for the other tumor markers evaluated. Conclusions. The only tumor markers to predict for response to chemotherapy were p53 at init ial surgery (P = 0.058) and Ki67 indices at secondary surgery (P = 0.0 01). Expression of steroid hormone receptors, TNF alpha, and P-glycopr otein and overexpression of c-erb-B-2 or EGFR are not associated with chemoresistance. (C) 1998 Academic Press.