Relationship between VEGF protein expression and lymph node metastasis in papillary thyroid carcinoma among Asians: a meta-analysis.

We carried out the current meta-analysis of relevant cohort studies in an attempt to investigate the relationships between vascular endothelial growth factor (VEGF) protein expression and lymph node (LN) metastasis in papillary thyroid carcinoma (PTC) among Asians. A range of electronic databases were searched, including Web of Science (1945∼2013), the Cochrane Library Database (Issue 12, 2013), MEDLINE (1966∼2013), EMBASE (1980∼2013), CINAHL (1982∼2013), and Chinese Biomedical Database (CBM) (1982~2013) with cross-referencing without language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratio (OR) with their 95 % confidence interval (95 %CI) was calculated. Twelve clinical cohort studies with a total of 1,045 PTC patients were included in our meta-analysis, The results of our meta-analysis revealed that patients with VEGF-positive tumors had a 3.02-fold higher risk of LN metastasis than that of patients with VEGF-negative tumors (OR=3.02, 95 %CI=2.05~4.43, P<0.001). Furthermore, subgroup analysis by country suggested that VEGF-positive expression was associated with an increased risk of LN metastasis in PTC patients among Chinese populations (OR=3.33, 95 %CI=2.30~4.83, P<0.001), but not among Korean, Turkish, and Japanese populations (all P>0.05). Our findings support the view that VEGF protein expression may be correlated with LN metastasis in PTC patients, especially among Chinese populations.