Clinical Significance of p53, P-glycoprotein, and Glutathione S transferase-pi in Advanced Non-Small Cell Lung Cancer.

Young Don Joo, Chang Hak Sohn

A retrospective study was performed o define the clninical significance of p53, P-glycoprotein (Pgp), and Glutathione S transferase-pi (GST-pi) immunohistochemical (IHC) expression in advanced non-small cell lung cancer (NSCLC). We reviewed fifty seven patients with advanced NSCLC who had undergone surgical resection or bronchoscopic biopsy between March 1997 and March 1999. IHC staining for p53, GST-pi, and Pgp was performed using formalin-fixed, paraffin-embedded specimens of the fifty seven patients. The IHC expression rate was 63% for p53, 28% for Pgp, and 53% for GST-pi, respectively. The median survival of the fifty seven patients was 45 weeks and the response rate was 38.6% (partial response, 22/57). The chemotherapy response and median survival of the p53 negative group (57% and 61 weeks) were better than those demonstrated by the p53 positive group (28% and 21 weeks) (p<0.05). Additionally, the GST-pi negative group showed a greater improvement of survival and response rate than the positive group (p<0.05). Pgp expression status appeared to have no significant differential effect on chemotherapy response and survival. These results suggest that immunohisto chemical staining of p53 and GST-pi may be useful in predicting the response to chemotherapy as well as survival in advanced NSCLC. However, this study is limited by its retrospective nature and the small numbers of tumors studied from a heterogenous group of patients.