Expression of ERCC-1 protein and its clinical implication in locally advanced cervical cancer

Objective To examine the protein expression of the nucleotide excision repair gene (ERCC-1) in patients with locally advanced cervical cancer and its relationship with the efficacy of radiotherapy and chemotherapy. Methods The expression of ERCC-1 protein in 88 patients with locally advanced cervical cancer treated in our hospital between 2007-2011 was measured using immunohistochemistry (IHC). The patients were divided into high-expression group (n=48) and low-expression group (n=40) based on the fluorescence intensity on the IHC staining. All patients received cisplatin (40 mg/m2 per week) during radiotherapy. The relationship between ERCC-1 protein expression and the clinicopathological factors of cervical cancer was analyzed using the chi-square test. Survival was calculated using the Kaplan-Meier method and compared by the log-rank test. Multivariate prognostic analysis was performed using the Cox model. Results The overall response rate (CR+ PR) was 81%(39/48) in the high-ERCC-1 expression group and 85%(34/40) in the low-ERCC-1 expression group (P=0.641). ERCC-1 protein expression was associated with recurrence and metastasis (P=0.043, 0.043). The 5-year survival rate was significantly higher in the low-ERCC-1 expression group than in the high-ERCC-1 expression group (65% vs. 42%, P=0.029). Conclusions Patients with high ERCC-1 protein expression are more likely to have local recurrence and distant metastasis than those with low ERCC-1 protein expression. ERCC-1 protein expression may be a clinically significant biomarker for predicting the prognosis of cervical cancer patients. Key words: Cervical neoplasms/three-dimensional radiotherapy; Cervical neoplasms/concurrent chemotherapy; Nucleotide excision repair gene; Immunohistochemistry