Evaluation of the Effect of ERCC1 Expression on Survival and Treatment Response in Patients with Advanced Gastric Cancer

Purpose: Gastric cancer is one of the leading causes of cancer-related deaths worldwide and is usually diagnosed at an advanced stage, resulting in poor prognosis. Therefore, identifying factors that influence survival and treatment response is important. Platinum-based chemotherapies are widely used in the treatment of gastric cancer, and nucleotide excision repair (NER) plays a key role in repairing platinum-induced DNA damage, with ERCC1 being a critical component of this pathway. ERCC1 expression has been suggested to affect treatment response and long-term survival in advanced gastric cancer patients receiving platinum-based therapy. This study aimed to evaluate the prognostic and predictive value of ERCC1 expression in advanced gastric adenocarcinoma. Patients and Methods: Forty-five patients diagnosed with HER-2 negative metastatic gastric adenocarcinoma and followed in the Oncology Clinic between October 2007 and May 2012 were retrospectively analyzed. ERCC1 expression was assessed by immunohistochemistry in tumor samples. Clinicopathological data, treatment regimens, progression-free survival (PFS), and overall survival (OS) were evaluated using Kaplan-Meier and multivariate analyses. Results: The median age was 63 years, and 64% of patients were male. Seventy-six percent received platinum-based therapy. The ERCC1 positivity rate was 38%. No significant difference in PFS was observed between ERCC1 positive and negative groups (both 5 months). OS was 11 months in the ERCC1-negative group and 7 months in the positive group; the 4-month difference was not statistically significant (p>0.05). In multivariate analysis, only treatment response was significantly associated with survival (p=0.0001). Conclusion: ERCC1 expression was not significantly associated with survival or treatment response. However, the 4-month OS difference may be clinically relevant. Larger prospective studies are needed to clarify the prognostic and predictive value of ERCC1 in gastric cancer.