Immunohistochemical Expression and Serum Levels of CD44 as Prognostic Indicators in Patients with Non-Small Cell Lung Cancer

Abstract

Background/Objectives: CD44 is often expressed in various types of tumor cells and involved in a number of biological behaviors of malignancy. The present study focused on the clinical significance of the expression of CD44st and CD44v6 in non-small cell lung cancer (NSCLC). Methods: The cohort consisted of 261 consecutive patients who had undergone complete resection of NSCLC. CD44 expression was evaluated in surgical specimens by immunohistochemical staining. Serum CD44 levels were determined using a sandwich ELISA (enzyme-linked immunosorbent assay). Results: In the immunohistochemical analysis, significant correlations were observed between CD44 expression and clinicopathological factors such as the T factor, N factor, pathological stage, and histological type. The 5-year survival rates according to CD44v6 expression were 65.8 and 80.6% in the higher and lower expression groups, respectively (p = 0.0053). According to ELISA, the group with higher expression of serum CD44v6 also showed a significantly more unfavorable prognosis than the lower expression group (p = 0.014). According to multivariate analysis using these significant variables, serum CD44v6 level was found to be an independent prognostic factor (p = 0.048). Conclusions: CD44v6 overexpression and higher serum CD44v6 levels were found to be significantly unfavorable prognostic factors.