Gene therapy is an experimental treatment used for a variety of medical conditions, including cancer. The technique uses viruses and other carriers (vectors) to transport healthy genes into human cells that contain defective or missing DNA. The treatment can restore a missing or altered function, or give the cell a new function. Gene therapy is the attempt to alter the problem of missing or damaged genetic material that contributes to the development of cancer in the human body.

Today, researchers are studying and testing numerous forms of gene therapy that may offer hope to cancer patients around the world. Some of the potential goals for gene therapy in the treatment of cancer are to:

• Change or fix an abnormal gene so that it functions normally.
  
  
• Inject healthy genes into cells to replace an absent gene or to compensate for one that is poorly functioning.
  
  
• Replace an abnormal gene with a normal one.

There are no proven methods to prevent or cure cancer using gene therapy. However, discoveries have been made regarding genes and their activities in cancer development. Methods of introducing genetic material into cells are varied, as are the results. Strategies include placing viral genetic material into tumors, which can override and change the defective genes of cancer cells. Techniques can also enhance the immune system to fight cancer and suppress the growth of blood vessels in malignant tumors to curb their growth.

Although gene therapy has shown great promise, it is important to remember that much more research is needed to produce safe, reliable and effective treatments of cancer.