Relevance of p53, bcl-2 and Rb expression on resistance to cisplatin-based chemotherapy in advanced non-small cell lung cancer.

Purpose: Tumors with p53 overexpression have been associated with enhanced resistance to cisplatin-based chemotherapy in a few and small studies involving non-small cell lung cancer. The relationships and interactions between p53, Rb and bcl-2 immunostaining, clinical parameters and response to cisplatin-based chemotherapy were evaluated in the present study.
Experimental Design: Histological specimens obtained by bronchial or fine-needle biopsy from patients who underwent cisplatin-based chemotherapy between 1992 and 1999 were evaluated by immunostaining.
Results: There were 102 patients, 88 men. Median age was 63 years; 47 had stage III and 55 stage IV disease. Forty-six tumor samples (45%) had positive immunostaining for p53, 61 (59%) had negative immunostaining for Rb and 8 (8%) had positive immunostaining for bcl-2. The response rate of the group with p53 positive immunostaining was 26% versus 57% of the p53 negative group (P=0.004). In multivariate analyses p53 positive immunostaining was identified as an independent predictive factor for resistance to cisplatin-based chemotherapy (P=0.006).
Conclusions: Our study confirmed an association of p53 immunostaining and response rate of patients treated with cisplatin-based chemotherapy.