VEGFA and metastatic malignant neoplasm in the lymph nodes: A meta-analysis of 47 studies (3476 patients) indicated that VEGF overexpression in the tumor predicts poorer overall survival and progression free survival for patients with head and neck cancer, and also correlates with high risk of lymph node metastases [27], however, the relationship between circulating VEGF levels and outcome are not as straightforward [28, 29].