Excision Repair Cross-Complementing-1 for Small Cell Lung Cancer

Abstract

We read the article by Rossi et al.1Rossi G Nannini N Tiseo M ERCC1 and small cell lung cancer.J Thorac Oncol. 2010; 5: 1876-1877Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar in the November issue of the Journal of Thoracic Oncology with great interest. In the article, the authors summarized six studies, including our previous study,2Kim YH Ishii G Goto K et al.Expression of breast cancer resistance protein is associated with a poor clinical outcome in patients with small-cell lung cancer.Lung Cancer. 2009; 65: 105-111Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar regarding the expression of excision repair cross-complementing-1 (ERCC1) in small cell lung cancer. Overall, the expression of ERCC1 was not correlated with the response to platinum-based chemotherapy; however, low expression of ERCC1 was significantly associated with good prognosis in patients with limited disease (LD) in three studies. Based on these data, they speculated that ERCC1 expression is a prognostic rather than a predictive marker of response to platinum-based chemotherapy only in patients with LD; however, they did not take account of the influence of radiotherapy. The proportion of patients who received thoracic radiotherapy was reported in two of the three studies, excluding the study by Rossi et al.,1Rossi G Nannini N Tiseo M ERCC1 and small cell lung cancer.J Thorac Oncol. 2010; 5: 1876-1877Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar with 35 of 40 (87%) and 38 of 45 (84%) patients with LD receiving thoracic radiotherapy in the study by Lee et al.3Lee HW Han JH Kim JH et al.Expression of excision repair cross-complementation group 1 protein predicts poor outcome in patients with small cell lung cancer.Lung Cancer. 2008; 59: 95-104Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar and Ceppi et al.,4Ceppi P Longo M Volante M et al.Excision repair cross complementing-1 and topoisomerase IIalpha gene expression in small-cell lung cancer patients treated with platinum and etoposide: a retrospective study.J Thorac Oncol. 2008; 3: 583-589Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar respectively. Although the precise mechanism remains to be elucidated, previous in vitro studies have shown that low ERCC1 expression is associated with a high sensitivity to radiation5Murray D Vallee-Lucic L Rosenberg E et al.Sensitivity of nucleotide excision repair-deficient human cells to ionizing radiation and cyclophosphamide.Anticancer Res. 2002; 22: 21-26PubMed Google Scholar; therefore, patients who received thoracic radiotherapy were excluded from analysis in our study.2Kim YH Ishii G Goto K et al.Expression of breast cancer resistance protein is associated with a poor clinical outcome in patients with small-cell lung cancer.Lung Cancer. 2009; 65: 105-111Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar To date, many studies have been reported concerning the expression of ERCC1 also in non-small cell lung cancer; however, the results are diverse, there is no consensus, and it has not been accepted for clinical use. The role of ERCC1 is complex, and further studies are necessary for better understanding of the function of ERCC1 in both chemoresistance and radioresistance.