It can occur through two mechanisms: (1) tumor cell secretion of VEGF and other cytokines that increase capillary permeability and promote angiogenesis, and (2) occlusion of the lymphatic conduit by cancer cells, which can increase the hydrostatic pressure, disrupt the flow of lymphatic effusions, reduce water and protein absorption, and lead to fluid retention in the serous cavity [20, 21]. This evidence concerns the gene VEGFA and cancer.