Immunohistochemical expression of excision repair cross-complementing 1 (ERCC1) in non-small-cell lung cancer: implications for patient outcome

The identification of novel prognostic markers may help to better assess survival probability in different subgroups of patients with non-small-cell lung cancer (NSCLC) and to tailor treatment according to the molecular profile of the tumour. We sought to examine whether the immunohistochemical expression of excision repair cross-complementing 1 (ERCC1), an essential component of the nucleotide excision repair pathway, may predict prognosis in NSCLC. Formalin-fixed paraffin-embedded tumour samples from 44 Turkish patients with NSCLC treated by adjuvant platinum-based chemotherapy were included in the study. Immunohistochemical expression levels of ERCC1 were correlated with clinical outcomes by Kaplan-Meier curves and multivariable Cox proportional hazards regression analysis. A total of 29 patients had ERCC1-negative tumours while 15 had ERCC1-positive tumours. The mean progression-free survival (PFS) was significantly lower in patients with ERCC1-positive tumours (13 +/- 2 months) than in those with ERCC1-negative tumours (27 +/- 5 months, p < 0.05). Similarly, the mean overall survival (OS) was significantly lower in patients with ERCC1-positive tumours (20 +/- 3 months) than in those with ERCC1-negative tumours (33 +/- 5 months, p < 0.05). After allowance for potential confounders, Cox regression analysis demonstrated that ERCC1 expression was significantly associated with both PFS and OS (both p < 0.05). This study provides support for the prognostic value of ERCC1 immunohistochemical expression in patients with NSCLC treated by adjuvant platinum-based chemotherapy. If independently confirmed, these findings may improve prognostic stratification in this group of patients.