The prognostic value of CD44 expression in gastric cancer: a meta-analysis

Several studies have been conducted to examine the association between CD44 expression and the prognosis of gastric cancer (GC). However, the conclusions remain controversial. We conducted a meta-analysis study of 16 published studies with 2403 patients to evaluate the correlation between CD44 expression and clinicopathological characteristics and overall survival of the GC patients. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were used to assess the correlation of CD44 expression with the clinicopathological features of GC patients. Hazard ratios (HRs) with their 95% confidence intervals (CIs) were used to assess the association between CD44 and prognosis of GC patients. Total CD44 expression was detected in ten studies, and CD44v5 and CD44v6 expressions were detected in one and five papers, respectively. The results revealed that CD44 expression was associated with some clinicopahological features, such as lymph node metastasis (pooled OR=1.81, 95% CI=1.44-2.34, P=0.000), distant metastasis (pooled OR=3.29, 95% CI=1.90-5.67, P=0.001) and TNM stage (Pooled OR=1.84, 95% CI=1.13-2.99, P=0.014). Moreover, we also found that GC patients with positive CD44 expression had a worse prognosis than the ones with negative CD44 expression (HR=1.93, 95% CI=1.54-2.42, P=0.000). In stratified analysis, the combined HR with CD44 and CD44v6 was 2.20 (95% CI=1.81-2.67) and 1.70 (95% CI=1.00-2.90), respectively. These results suggested that positive CD44 expression could predict a lower overall survival rate and could be an independent dangerous prognostic factor in GC patients.