Gene Therapy Tested to Fight Cancer Fifteen failures and two successes may not seem like a winning record, but for a highly unusual experimental treatment, 15 and 2 is a very promising start in what could prove to be the opening round of a revolution in cancer therapy.
The idea is ingenious: Combine a cancer-fighting cell with a virus that seeks out cancer. But of course, it's only ingenious if it works.
Types of white blood cells called lymphocytes are the body's first line of defense against cancer. Your immune system responds to the growth of cancerous cells with lymphocytes that control early cancer growth. But they can control advanced cancer - especially cancer that's spread to other parts of the body.
Researchers at the National Cancer Institute (NCI) devised a unique plan to make lymphocytes more effective. First, they genetically engineered a virus to perform two tasks: 1) aggressively hunt for cancer cells, and 2) attach to the cells. Then they extracted blood from 17 patients with advanced cases of treatment-resistant, malignant melanoma that had metastasized to other organs. Cells of the genetically enhanced virus were coupled with lymphocytes. The result: A cancer fighter hitching a ride with a tenacious cancer hunter.
Individual blood draws were then returned to each patient's body.
Two of the subjects showed dramatic responses. In one patient, the therapy reduced a cancerous mass in the liver to a size that could be safely removed with surgery. In the other patient, lung tumors disappeared completely. Researchers report that 18 months after the treatment, both men are cancer-free, and they still have high levels of the genetically enhanced lymphocytes in their blood.
Even though 15 patients in the NCI study didn't respond to the experimental therapy, researchers still consider the trial a success.
Lead researcher Dr. Steven Rosenberg explained to Food Consumer that this first test in humans is just the beginning of a great deal of work that will be required to refine the variables. Future trials are already in the planning stages for patients with lung, breast and colon cancers. Meanwhile, Dr. Rosenberg and his colleagues are currently trying to boost lymphocyte effectiveness in time to give the other 15 patients an additional treatment.
Dr. Rosenberg believes that this revolutionary treatment might eventually be useful in about half of all common cancers. Of course, I'll be keeping a close watch for upcoming studies from the NCI team, and I'll report to you about the progress they're making. Sources:
"Gene Therapy Successfully Fights Deadly Skin Cancer" Kathy Jones, Food Consumer, 8/31/06, foodconsumer.org
"Therapy Turns Patients' Cells into Cancer Smart Bombs" Christy Feig, CNN, 8/31/06, cnn.com |
