Background:
Radiation therapy is a widely employed modality which is used to destroy cancer cells, but it also
tends to induce changes in the tumor microenvironment and promote angiogenesis. Radiation when used as a sole means of
therapeutic approach to treat cancer, tends to trigger the angiogenic pathways, leading to the upregulation of several
angiogenic growth factors such as VEGF, bFGF, PDGF and angiogenin. This uncontrolled angiogenesis leads to certain
angiogenic disorders like vascular outgrowth and increase in the tumor progression that can pose a serious threat to patients.
Objective:
This review emphasizes on various components of the tumor microenvironment, angiogenic growth factors and
biological effects of radiation on tumors in provoking the relapse. It also describes the angiogenic mechanisms that trigger
the tumor relapse after radiation therapy and how angiogenesis inhibitors can help in overcoming this phenomenon. It gives
an overview of various angiogenesis inhibitors in pre-clinical as well as in clinical trials.
Conclusion:
The review focuses on the beneficial effects of combinatorial therapeutic approach of anti-angiogenesis therapy
and radiation in tumor management.