Association of EGFR mutations with low BRCA1 gene expression in non-small cell lung cancer.

Clinical studies suggest that the mRNA expression level of excision repair cross complementing group 1 gene (ERCC1) is associated with epidermal growth factor receptor (EGFR) mutation and breast cancer susceptibility 1 gene (BRCA1) mRNA expression in non-small cell lung cancer (NSCLC). In this study, the correlation between EGFR mutation status and ERCC1 and BRCA1 gene expression in Chinese NSCLC patients was examined. Real-time polymerase chain reaction (PCR) and direct sequencing were used to detect mRNA expression levels and EGFR mutation status, respectively in microdissected formalin-fixed paraffin-embedded non-small cell lung cancer tissues. EGFR mutations were detected in 27/103 patients (26.2%) and were found to be gender-related (P=0.001). The BRCA1 mRNA expression level was associated with histology, while there was no association with ERCC1. For the EGFR mutant-type, a high BRCA1 gene expression was detected in 2 cases (20.0%) and a low expression in 8 cases (80.0%), while for EGFR wild-type, a high BRCA1 gene expression was detected in 20 cases (43.5%) and a low expression in 26 cases (56.5%). There was no difference in the one-year survival period, according to results obtained for either the ERCC1 or BRCA1 mRNA expression levels. EGFR mutations in NSCLC samples are more likely to express low ERCC1 and BRCA1 mRNA levels. In these latter samples, a statistically significant difference was observed. However, to examine their correlation and clinical outcomes, additional studies are required.