BIOM-15. SERUM AMYLOID-β42 AS A NONINVASIVE BIOMARKER FOR PROGNOSIS AND HISTOLOGIC FEATURES OF GLIOMA

Abstract

Abstract INTRODUCTION Glioma is the most common primary tumor in central nervous system and is often refractory. Histopathologic examination is essential to establish initial diagnosis, and multiple imaging studies are conducted to assess for treatment response. However, those conventional approaches usually accompanies high risks and costs during treatment. The purpose of this study is to find a novel candidate of noninvasive biomarker for histologic prediction and prognostic assessment of glioma. METHODS Serum was prepared from blood samples collected preoperatively from 65 patients with WHO grade II–IV glioma from October 2004 to December 2017 in a single tertiary-level institution. Concentration of amyloid beta-42 (Aβ42) was measured by SMCxPRO (Merck) immunoassay. Clinical characteristics and histologic features of the patients including the molecular subtype were reviewed. Progression-free survival has been evaluated for the primary outcome. RESULTS The mean age of the patients was 53.7±12.2 years. 37 (56.9%) patients were males and 21 (32.3%) cases were primary tumors. In Kaplan-Meier survival analysis, higher serum Aβ42 (>5.7 pg/ml) group showed poor outcome with a statistical significance (p=0.014). In multivariate regression analysis, the concentration of serum Aβ42 showed a significant association with EGFR expression, or Ki-67 labeling index. The higher concentration of serum Aβ42 was associated with EGFR wild type (odds ratio 0.237, p=0.022), high cell proliferation (β=0.339, p=0.007) and poor outcome (hazard ratio 0.339, p=0.046). CONCLUSION Serum Aβ42 level is a possible good candidate of noninvasive biomarkers for prediction of histologic features and prognosis in glioma patients. Further studies with large cohorts might be mandatory for the clinical use of Aβ42.