Targeted Therapy for Brain Tumors
Traditional treatments for brain tumors are surgery, chemotherapy, and radiation. Although potentially lifesaving, these therapies can do considerable damage to healthy cells and tissue.
New targeted therapies, however, may be able to zero in on tumor cells while leaving healthy cells alone, providing a more effective treatment. Certain targeted therapies use various molecules to eliminate or reduce tumor cells or block their destructive behavior. Most are still in the research stages.
Drugs that target tumor growth
Also called antiangiogenic compounds, these are medications that can slow or stop a brain tumor's ability to spread and divide. They do this by disrupting angiogenesis, the process by which blood vessels grow to supply the tumor. They can block the delivery of oxygen and nutrients to the tumor and may also interfere with cell signaling and make it hard for tumor cells to migrate to different parts of the body.
Researchers are studying how well these medications work in combination with traditional brain tumor treatments. Because these drugs focus on growing cancers, they may have fewer side effects than ordinary chemotherapy drugs. Compounds are currently being tested in clinical trials.
Gene-based therapy and screening
Oncogenes are abnormal genes that can cause cancer by stimulating excessive cell growth in the body. Researchers are currently investigating just how these genes become damaged. They are also developing tools to screen for them.
Another experimental treatment for cancer along these lines is gene therapy, a process that involves replacing missing or abnormal genes with healthy ones. One approach to gene therapy is to introduce a "suicide gene" into a tumor cell, causing its destruction. Currently, gene therapy is available only through clinical trials.
The two types of cancer vaccines are preventive vaccines, which help protect healthy people against a cancer, and treatment vaccines, which boost the body's immune response to cancer cells. Currently available vaccines help prevent cervical and liver cancers and treat some types of prostate cancer. Vaccines to treat brain cancer tumors are being tested now.
These therapies use the body's natural immune response to help fight cancer. For the treatment of brain tumors, researchers are studying the effectiveness of interleukins, which are protein molecules that stimulate the growth of immune cells, which, in turn, destroy cancer cells. Another biological therapy being studied for brain tumors uses colony-stimulating factors, or substances that encourage bone marrow stem cells to divide, creating blood cells that boost the body's immune system and reduce the need for a transfusion. This would enable doctors to increase doses of anticancer drugs without increasing the risk for infection and other complications.
Growth factors are substances in the body that regulate cell growth. Cancerous cells may secrete growth factors or react to them, which allows them to grow out of control. Drugs are currently being developed to block the effects of these growth factors by interfering with signaling pathways. Many growth factor therapies have been approved by the FDA to treat certain types of cancers. Scientists are now doing research to see if such drugs might help in the treatment of brain tumors.