Suspension biochip versus immunohistochemistry for ERCC1 and RRM1 detection in non-small cell lung cancer

Objective: With the treatment of non-small cell lung cancer (NSCLC) entering the era of individualization through the detection of expression levels of promising biomarkers in NSCLC tumor samples, tailored chemotherapy, and prognosis evaluation for NSCLC patients are now possible. This study focuses on two commonly utilized detection methods: immunohistochemistry (IHC) and suspension biochip. This study aims to determine the differences between IHC and suspension biochip with regard to the expres- sion levels of biomarkers. Methods: Forty-two NSCLC patients were enrolled into the study from April 2011 to June 2012. The expres- sion levels of excision repair cross-complementing group 1(ERCC1) and ribonucleotide reductase (RRM1) in the tumor samples were tested through IHC and suspension biochip, respectively. The statistical methods used in the analysis were were performed with the SPSS (version 17.0) statistical software; P < 0.05 was considered statistically significant. Results: The consistent rates of the ERCC1 and RRM1 expression levels tested by IHC and suspension biochip were 52.3% (22/42) and 76.2% (32/42), respectively. A significant correlationship was observed between IHC and suspension biochip in terms of the RRM1 expression levels (r=0.778, P=0.01). No such correlationship was found in the ERCC1 expression levels (r=0.277, P=0.076). Conclusion: The expression levels of RRM1 tested by the two methods exhibited good correlationship. The expression levels of the RRM1 mRNA in the NSCLC tissues were consistent with RRM1 protein expression. No significant correlationship was found in the expression levels of ERCC1 tested by the two methods. The expression levels of the ERCC1 mRNA in the NSCLC tissues were not always correlated with ERCC1 protein expression. The simulta- neous use of IHC and suspension biochip can increase the sensitivity and specificity of chemotherapy.