31P - Plasma CRABP2 in Patients with Non-Small Cell Lung Cancer

Abstract

Aim: Lung cancer is the leading cause of death in patients with malignancy. So we found out new gene, CRABP2 (cellular retinoic acid binding protein 2), in lung cancer tissues of cigarette smokers by RNA-sequencing methods. CRABP2 encodes cellular retinoic acid binding protein 2, which acts as a cytosol-to-nuclear shuttle protein to facilitate retinoic acid binding to its site cognate receptor complex and transfer of the complex to nucleus. We performed this study to know that plasma CRABP2 could be used as diagnostic and prognostic markers in patient with NSCLC. Methods: 122 patients with NSCLC were enrolled between September 2009 and September 2013. We selected controls from Korea Biobank Network. We selected controls without any malignancy, any pulmonary disease and 1:1 matched with age (±5 yrs), sex and cigarette smoking history (± 10 pack-years, PY). Blood samples were collected at the time of diagnosis before any treatment modality. We were measured plasma levels using commercially available enzyme-linked immunosorbent assay (ELISA) kits for CRABP2. Results: The mean age of NSCLC patients was 71.8 ± 8.9 years, and the mean cigarette smoking history was 34.2 ± 32.4 PY. Men were 95 (77.9%). Matched controls and patients with NSCLC presented no differences in age, sex and smoking history. The mean plasma level of CRABP2 were 37.36 ± 28.75 ng/mL in the NSCLC patients and 24.09 ± 21.09 ng/mL in the matched controls (p < 0.001). There was no difference in the plasma level of CRABP2 between patients with adenocarcinoma and those with squamous cell carcinoma. The plasma level of CRABP2 did not differ significantly according to TNM staging. There was no difference in overall survival rates according to plasma level of CRABP2. Conclusions: Plasma CRABP2 levels were significantly elevated in patients with NSCLC as compared matched controls. So we suggest that CRABP2 can be new biomarker of NSCLC. Disclosure: All authors have declared no conflicts of interest.