Clinical significance of ERCC1 expression in advanced squamous cell carcinoma of the head and neck treated with cisplatin- based concurrent chemoradiation

Abstract

6061 Background: The cytotoxic effect of cisplatin is based on the DNA cross linking. Nucleotide excision repair is associated with resistant to platinum-based chemotherapy. The excision repair cross-complementation group 1 (ERCC1) enzyme plays a rate-limiting role in nucleotide excision repair pathway. We evaluated the expression of ERCC1 as a predictive factor for survival in patients of squamous cell carcinoma of the head and neck (SCCHN) treated with cisplatin-based concurrent chemoradiotherapy (CCRT). Methods: We reviewed the clinical records and pathologic specimens of locally advanced SCCHN patients who had been treated with cisplatin-based definitive CCRT between 1995 and 2005. ERCC1 expression of the biopsy specimen was assessed by immunohistochemical (IHC) staining and a semi- quantitative grading system (H-score) was used for the evaluation. The median value of the H-score was chosen as the cutoff point for positive ERCC1 expression. Results: A total of 44 specimens and clinical data of the patients were reviewed. The median age was 59 years (range; 27–75), and 81.8% were male; 94.2% had ECOG performance status 0–1. The positive ERCC1 expression rate was 54.5% of all specimens (N=24/44). Overall tumor response rate for CCRT was 90.9% (CR=65.9%; PR=25.0%). With a median follow-up of 45.9 months (range; 5.4–133.0), 5-year progression free survival (PFS) rate was 58.0% and 5-year overall survival (OS) rate was 57.2%. Patients in group of positive ERCC1 expression showed poor survival in terms of PFS and OS (p=0.04; p=0.05), compared with negative ERCC1 expression group. Conclusions: The positive ERCC1 expression might be a predictive factor for poor survival and early progression in patients with locally advanced SCCHN treated with cisplatin-based CCRT. No significant financial relationships to disclose.