Background: Although both excision repair cross-complementing group 1 (ERCC1) and breast cancer susceptibility gene 1 (BRCA1) can be effective biomarkers for chemosensitivity in primary malignant tumors, their applicability to metastases is poorly understood. Here, ERCC1 and BRCA1, which are linked to lymph node metastasis (LNM) in colorectal cancer (CRC), were evaluated in primary CRC samples from Chinese patients with LNM (LNM CRC) or without LNM (non-LNM CRC). mRNA levels of ERCC1 and BRCA1 in CRC samples, and their relationships to primary CRC and LNM, were also examined.
Methods: Differences in BRCA1 and ERCC1 gene expression between primary CRC with or without LNM were assessed in CRC samples from 120 Chinese patients, using real-time polymerase chain reaction. Relationships between ERCC1 and BRCA1 expression and clinicopathological parameters and prognoses were also examined.
Results: ERCC1 and BRCA1 were significantly down-regulated in LNM CRC compared with non-LNM CRC. Down-expression of ERCC1 and BRCA1 was significantly associated with LNM (P < 0.001), advanced TNM stage (P < 0.001), and decreased 5-year overall survival rate (P < 0.001). Univariate and multivariate analyses showed ERCC1 and BRCA1 expression as independent predictors of recurrence and survival in CRC patients (P < 0.05).
Conclusions: ERCC1 and BRCA1 mRNA expression levels correlate inversely to CRC metastasis. ERCC1 and BRCA1 might serve as biomarkers for LNM and as prognostic indicators for CRC; their down-expressions are predictors of poor outcome in CRC patients.