Clusterin immuno-expression and its clinical significance in patients with non-small cell lung cancer.

Abstract

e17520 Background: Clusterin is an enigmatic glycoprotein with a nearly ubiquitous tissue distribution. It plays important roles in various pathophysiological processes, including tissue remodeling, reproduction, lipid transport, complement regulation and apoptosis. Clusterin appears to have two main isoforms which are the result of alternative splicing. The secreted form and nuclear form of clusterin were reported to have different roles in human malignancies. The purpose of this study was to examine Clusterin immuno-expression and its clinical significance in a subgroup of Chinese patients with non-small cell lung cancer. Methods: Tissue samples from the primary tumors were obtained from 121 patients with completely resected non-small cell lung cancer. The expression of clusterin protein was analyzed by immunohistochemical staining with an antibody recognizing all isoforms of clusterin. Staining patterns were observed and graded based on intensity and density and correlated with clinical and pathological data. Results: Cytoplasmic and nuclear immnunostaining of clusterin were both observed in this subgroup of patients. Tumors from 70 patients (57.9%) exhibited only positive cytoplasmic staining. Tumors with positive nuclear staining only were observed in 27 patients (22.3%). 16 cases (13.2%) were with both nuclear and plasmic staining. Significant association was observed between positive cytoplasmic expression and histologic type as indicated adenocarcinoma was more likely with only positive cytoplasmic staining. The clusterin immuno-staining was not associated with patients DFS or OS by univariate or multivariate analysis. For patients with chemotherapy, those with positive cytoplasmic staining only had worse survival than other patients. Conclusions: Both plasmic and nuclear immunostaining were observed in tumors of patients with NSCLC. Adenocarcinoma was more likely with positive cytoplasmic staining only. The immuno-expression of clusterin was not associated with the prognosis of this subgroup of patients and patients with only positive cytoplasmic immmunostaining of clusterin seemed to be more sensitive to chemotherapy. No significant financial relationships to disclose.