Brain Tumors: Primary - Other Treatments

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Highlights	Diagnosis	Other Treatments
Introduction	Common Brain Tumors	Treatment of Complications
Symptoms	Treatment	Resources
Risk Factors	Surgery	References
Causes	Radiotherapy
Prognosis	Chemotherapy

Other Drugs that Block Angiogenesis. Thalidomide was one of the first drugs used to inhibit angiogenesis and has undergone several trials. There is some evidence that it may work more effectively for metastasized brain tumors than primary tumors. Other drugs in early trials with various effects on tumor growth include suramin, cilengitide, semaxanib, PTK787, and atrasentan.

Other Investigative Drugs

Retinoids. Retinoids are vitamin A derivatives and act as differentiating drugs in cancer treatments. That is, they can convert immature, dividing tumor cells into mature cells, stopping tumor growth. Studies suggest that they have little benefits as single drugs. Combination with radiotherapy and other drugs may hold promise.

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Inactivated Viruses. Investigators are finding that certain genetically inactivated viruses, such as the poliovirus or herpesvirus, may prove to be valuable fighters of brain cancers. Such viruses can enter cells and destroy them but do not pose any danger for infection. For example, one specially designed herpes virus targets the enzyme thymidine kinase (an enzyme that promotes tumor growth). Some researchers believe that a combination of this virus with retinoids may be effective with few serious side effects. Other viruses are being investigated. A drug based on this model is years away, however.

Immunotoxins. Drugs called immunotoxins use natural toxins to kill malignant brain cells.

Drugs that use diphtheria toxins, including TransMID-107R and DAB(389)EGF), are the first immunotoxins to show some promise. Clinical trials are investigating them for gliomas and metastatic brain cancers. Other toxins under investigation include irofulven (a mushroom toxin) and chlorotoxin (a substance derived from scorpions).

Taurolidine. Taurolidine is a unique drug that prevents tumor formation and growth in animals. An early clinical trial in patients with high-grade gliomas is under way.

Protein-Blocking Drug. Another development is the discovery of a protein called BEHAB (Brain-Enriched Hyaluronan Binding Protein). BEHAB is produced only by invasive glioma tumor cells, not by normal brain tissue or noninvasive tumor cells. Breakdown of BEHAB releases a substance called HABD (hyaluronan-binding domain), which appears to give glioma cells the ability to invade other areas of the brain. Both BEHAB and HABD represent potential targets for new therapies.