Expression of ERCC1 and class III ß-tubulin in resected non-small cell lung cancer and its correlation with platinum-based adjuvant chemotherapy.
ABSTRACT To explore the relationship between the expression of excision repair cross-complementation group 1 (ERCC1) and class III ß-tubulin and the clinical characteristics and overall survival of patients with non-small cell lung cancer (NSCLC).
Immunohistochemical analysis was used to determine the protein expression of ERCC1 and class III ß-tubulin in 160 completely resected NSCLC primary tumor samples, 50 of which were paired with adjacent normal tissue samples and another 40 benign lung lesion tissue samples as controls. Clinical data at baseline, disease-free survival and overall survival were also collected. Univariate and multivariate Cox models were used to analyze the risk factors.
In 160 tumor samples, the ERCC1 and class III ß-tubulin positive rates obtained with immunohistochemistry were 46.9% and 49.4%, respectively. Both biomarkers had a higher positive rate in male patients. For patients who did not receive adjuvant chemotherapy, ERCC1 positivity was associated with longer survival (median survival time 73 vs 53 months, p=0.041), while in patients treated with platinum chemotherapy, ERCC1 positivity tended to be associated with poor survival (median survival time 41 vs 54 months, p=0.014). Class III ß-tubulin positivity was also associated with poor survival (median survival time 38 vs 58 months, p<0.001), but had no influence on the survival of patients who did not receive adjuvant chemotherapy.
ERCC1 and class III ß-tubulin could be important survival predictors for completely resected NSCLC patients treated with adjuvant chemotherapy. Further prospective studies need to be performed to test this hypothesis in Chinese patients.
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ABSTRACT: The excision repair cross-complementation group 1 (ERCC1) protein is a potential prognostic biomarker of the efficacy of cisplatin-based chemotherapy in non-small-cell lung cancer (NSCLC). Although several ongoing trials are evaluating the level of expression of ERCC1, no consensus has been reached regarding a method for evaluation. We used the 8F1 antibody to measure the level of expression of ERCC1 protein by means of immunohistochemical analysis in a validation set of samples obtained from 494 patients in two independent phase 3 trials (the National Cancer Institute of Canada Clinical Trials Group JBR.10 and the Cancer and Leukemia Group B 9633 trial from the Lung Adjuvant Cisplatin Evaluation Biology project). We compared the results of repeated staining of the entire original set of samples obtained from 589 patients in the International Adjuvant Lung Cancer Trial Biology study, which had led to the initial correlation between the absence of ERCC1 expression and platinum response, with our previous results in the same tumors. We mapped the epitope recognized by 16 commercially available ERCC1 antibodies and investigated the capacity of the different ERCC1 isoforms to repair platinum-induced DNA damage. We were unable to validate the predictive effect of immunostaining for ERCC1 protein. The discordance in the results of staining for ERCC1 suggested a change in the performance of the 8F1 antibody since 2006. We found that none of the 16 antibodies could distinguish among the four ERCC1 protein isoforms, whereas only one isoform produced a protein that had full capacities for nucleotide excision repair and cisplatin resistance. Immunohistochemical analysis with the use of currently available ERCC1 antibodies did not specifically detect the unique functional ERCC1 isoform. As a result, its usefulness in guiding therapeutic decision making is limited. (Funded by Eli Lilly and others.).New England Journal of Medicine 03/2013; 368(12):1101-10. · 51.66 Impact Factor