Tumor microvasculature and microenvironment: targets for anti-angiogenesis and normalization
1Edwin L. Steele Laboratory, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, 100 Blossom Street-Cox 7, Boston, MA 02114, USA. dai@steele.mgh.harvard.edu
Microvascular Research
|June 15, 2007
Summary
Tumor blood vessels are abnormal, hindering drug delivery and promoting metastasis. Anti-angiogenic treatments can normalize tumor vasculature, improving treatment effectiveness and potentially synergizing with chemotherapy.
Area of Science:
- Oncology
- Vascular Biology
- Cancer Therapeutics
Background:
- Solid tumors exhibit abnormal vasculature, differing significantly from normal tissue blood vessels.
- Tumor blood vessels are characterized by leaky, heterogeneous, and compromised blood flow, alongside non-functional lymphatic vessels.
- These vascular abnormalities elevate interstitial fluid pressure, creating physiological barriers to therapeutic agent delivery and potentially promoting metastasis.
Purpose of the Study:
- To investigate the role of tumor vasculature in therapeutic resistance and metastasis.
- To explore the potential of normalizing tumor vasculature through anti-angiogenic strategies.
- To evaluate the synergistic effects of combining anti-angiogenic therapy with cytotoxic treatments during vascular normalization.
Main Methods:
- Review of existing literature on tumor vasculature, angiogenesis, and therapeutic delivery.
- Analysis of preclinical and clinical data on anti-angiogenic treatments.
- Examination of host-tumor interactions influencing angiogenic factor balance.
Main Results:
- Abnormal tumor vasculature impairs drug delivery and creates a hostile microenvironment (hypoxia, acidosis), reducing treatment efficacy.
- Elevated interstitial fluid pressure and impaired lymphatic drainage contribute to metastasis.
- Anti-angiogenic therapies have shown potential in transiently normalizing tumor vasculature and microenvironment.
- Combination therapy during vascular normalization windows demonstrated synergistic anti-tumor effects.
Conclusions:
- Restoring the balance of pro- and anti-angiogenic factors can normalize tumor vasculature and improve its function.
- Targeting tumor angiogenesis offers a promising strategy to overcome therapeutic barriers and enhance treatment outcomes.
- Combining anti-angiogenic therapy with conventional treatments during specific therapeutic windows may significantly improve patient prognosis.
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