Prognostic value of CD44 and CD44v6 expression in patients with non-small cell lung cancer: meta-analysis

We sought to clarify the prognostic value of CD44 in survival of patients with non-small cell lung cancer (NSCLC). We performed a meta-analysis of relevant literature to aggregate the available survival results, using studies published in English until March 2014. Eligible studies dealt with CD44, CD44 standard form (CD44s) and CD44 variant 6 (CD44v6), assessment in NSCLC patients on primary lesions and reported survival data according to CD44 and CD44 isoforms expression. We aggregated 10 trials (5 trials for CD44v6, 3 trials for CD44, and 2 trials for CD44s) comprising 1,074 patients, in this meta-analysis. The combined hazard ratio (HR) with CD44v6 and CD44s was 2.39 (95 % confidence interval (CI) 1.69-3.37) and 1.64 (95 % CI 1.06-2.52), respectively. It associated high CD44v6 and CD44s expression with poor survival in NSCLC patients. However, CD44 overexpression did not significantly correlate with survival in patients with NSCLC (HR 1.44; 95 % CI 0.72-2.89). Our meta-analysis shows that CD44v6 and CD44s overexpression indicates poor prognosis for NSCLC patients. However, the high CD44 expression is not significantly correlated with survival for patients with NSCLC.