Heterogeneity of excision repair cross-complementation group 1 gene expression in non-small-cell lung cancer patients

Abstract

Abstract. Excision repair cross-complementation group 1 (ERCC1) gene expression analysis is currently used widely in the molecular diagnosis of cancer. According to numerous studies, ERCC1 gene expression correlates with overall survival and effectiveness of chemotherapy with platinum agents. However, the degree of this correlation differs among various studies, with certain authors reporting a complete lack of such a correlation. These contradictions may be attributed to a number of factors, including the heterogeneity of the tumor tissue. In this study, we attempted to assess the degree of genetic heterogeneity exhibited by tissue samples obtained from non-small-cell lung cancer (NSCLC) through the expression of the ERCC1 gene. This study included 25 samples of tumor tissue from patients with a morphologically confirmed NSCLC diagnosis. A total of three randomized sections of each specimen were used. The ERCC1 gene expression was assessed by quantitative polymerase chain reaction (qPCR) in the TaqMan format. When planning the experiment and analysis of qPCR data, the MIQE guidelines were taken into consideration. We established that the coefficient of variation of the relative level of ERCC1 gene expression in the majority of the samples exceeded 33% (P<0.05), indicating the significant heterogeneity of the sample. We also demonstrated that the degree of heterogeneity of the tumor tissue is largely dependent on disease stage.

Relationship Between Xanthine Oxidoreductase Activity and BRCA1 Levels in Patients with Stage IIIA and IIIB Non-Small Cell Lung Cancer Being Treated with Neoadjuvant Chemotherapy

“…While it was reported in previous studies that chemotherapy causes the tumor tissues of markers, such as ERCC1, to shrink in various degrees. 10 In this study, the subjects were noted as positive for BRCA1 instead of negative. It is difficult to say that chemotherapy or radiotherapy does not have any effect on the IHC expression of this marker since there was a small number of positive BRCA1, just opposite to the data in previous literature.…”

Correlation Analysis and Prognostic Impact of 18F-FDG PET and Excision Repair Cross-Complementation Group 1 (ERCC-1) Expression in Non-Small Cell Lung Cancer

“…Previous studies have shown that NSCLC patients on platinum-based chemotherapy with increased ERCC-1 expression have lower survival compared with ERCC-1-negative patients [14]. However, because ERCC-1 expression within primary lesions and metastases can be heterogenous [15], and invasive procedures are needed for adequate amounts of specimen for immunohistochemistry, correlation between ERCC-1 expression with non-invasive metabolic imaging may be beneficial in determining therapeutic strategy.…”