Influence of Hypoxia and Neoangiogenesis on the Growth of Pancreatic Cancer

As with other solid tumors, the growth and metastasis of pancreatic cancer is critically dependent on tumor angiogenesis. A major stimulus for a tumor's recruitment of additional blood vessels is cellular hypoxia, a condition which is especially pronounced in this neoplasm. Hypoxia induces transcriptional activation of genes that alter cellular metabolism and promote neoangiogenesis. Pancreatic cancer cells have demonstrated activation of such adaptive pathways even in the absence of hypoxia. A highly-angiogenic response in this neoplasm correlates with increased tumor growth, increased metastasis, and decreased survival. Pancreatic cancers expressing high levels of vascular endothelial growth factor, a potent pro-angiogenic cytokine, also have a higher incidence of metastasis and poorer prognosis. Pancreatic cancer cells uniquely express receptors for vascular endothelial growth factor, indicating a role for an autocrine loop in tumor proliferation and invasion. Multiple experimental anti-angiogenic strategies, many of which target vascular endothelial growth factor, reduce pancreatic cancer growth, spread, and angiogenesis. Anti-angiogenic treatments for pancreatic cancer will likely be most effective when used as an integral part of a combination chemotherapeutic regimen.