If the genes that help maintain the repair of DNA are lost or not functioning, the likelihood that a damaged gene will be repaired decreases drastically. Tumor cells often have defects in the way DNA gets repaired. Scientists have started to find ways to change patients' genetic material to fight or prevent disease. Gene therapy is the process of supplying cells with healthy copies of missing or flawed genes. With this approach, the genetic makeup of the patient's cells is corrected, instead of giving the patient drugs to treat or control the disease.
Gene therapy is new and experimental.
This advance offers much hope for improving cancer treatment in the future. Current gene therapy experiments involve taking cells from the blood or bone marrow of the patient and growing them in the laboratory. The healthy copy of the missing or flawed gene is then inserted into the cells using a virus that is no longer harmful, called a disabled virus. Cells that have been successfully changed by this process are separated out, grown, and returned to the patient's body. In other cases fatty particles or disabled viruses are used to deliver the healthy gene directly to cells within the patient's body.