Decreased ERCC1 Expression After Platinum-Based Neoadjuvant Chemotherapy in non-Small Cell Lung Cancer

We have already demonstrated in a small cohort of 17 non-small cell lung cancer patients that ERCC1 (excision repair cross-complementation group 1) protein expression decreased after platinum-based treatment, however, certain clinicopathological parameters, such as histologic subtypes, ERCC1 expression scores, chemotherapeutic combinations, response rate, gender and smoking history were not analyzed. The aim of our present study was to extend the studied cohort and analyze those parameters. ERCC1 protein expression was examined in 46 patients treated with neoadjuvant chemotherapy. 46 bronchoscopic biopsy samples (27 squamous cell carcinomas /SCC/ and 19 adenocarcinomas /ADC/) together with their corresponding surgical biopsies were studied. ERCC1 immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissues. Staining scores were calculated by multiplying the percentage of positive tumor cells (0–100) by the staining intensity (0–3). 24/27 bronchoscopic SCC tissues expressed ERCC1. Thirteen of these cases became negative after neoadjuvant therapy and the expression differences between pre- and postchemotherapy samples were highly significant ( p