AOS22 Expression of excision repair cross complementation group 1 (ERCC1) protein in Indonesian patients with nasopharyngeal carcinoma receiving cisplatin-based adjuvant chemotherapy

Abstract

Background Overexpression of excision repair cross complementation group 1 (ERCC1) has been reported to be associated with resistance to platinum-based chemotherapy in head and neck cancer. Since cisplatin-based adjuvant chemoradiotherapy is the standard treatment for nasopharyngeal cancer (NPC) in Indonesia, it is important to investigate the role of ERCC1 as a possible predictive marker of disease progression in our patients. Methods Consecutive samples obtained from our pathology archives of NPC from 31 patients who were receiving standard treatment with cisplatin-based chemoradiotherapy were examined for ERCC1 expression by use of immunohistochemistry. A retrospective cohort study was done and overall survival curves (OS) were plotted versus expression of ERCC1. Findings ERCC1 expression was high in 16 (51.6%) patients and low in 15 (48.4%). There were no differences in the baseline characteristics between the two groups (age, sex, and stage of the disease; p > 0.05). Median survival was 15.5 months. Analysis of OS showed a significant difference between the two groups ( p = 0.02). A univariate analysis of the baseline characteristics and ERCC1 in relation to the 1 year OS showed that only ERCC1 was significant. 53.3% (95% confidence interval (CI) 40.4–66.2) of patients in the group with high ERCC1 expression had an OS of 1 year or more, whereas 80% (95% CI 69.7–90.3; p = 0.02) of the group with low ERCC1 expression had an OS of 1 year or more. The median 1 year OS in the high ERCC-1 group was 13.2 months (95% CI 0.0–27.2), whereas it was not achievable in the low ERCC-1 group. Hazard ratio for the group with high expression of ERCC1 was 3.304 (95% CI 1.12–9.71). Interpretation The low expression of ERCC1 might prolong the overall survival in Indonesian patients with NPC who are receiving standard cisplatin-based chemoradiotherapy. The authors declared no conflicts of interest.