Researchers at Stanford University have successfully delivered a “vaccine” directly to tumors in mice, eliminating all traces of cancer.
Developing a cancer vaccine is like finding the Holy Grail. This is the challenge that scientists around the world like those Stanford University Medical School are trying to meet. Their idea is to inject minute quantities (of the order of a millionth of a gram) of two immunostimulatory agents into solid cancerous tumors in mice, in an attempt to eliminate all traces of cancer in these rodents. And the experience is a success. Not only did this “vaccination” eliminate the tumor, but it would also have removed the untreated metastases.
The approach has worked particularly well in mice with lymphoma. The tests were reproduced here on 90 mice, and the researchers would have managed to eradicate the tumors in 87 of them. The cancer has reappeared in three mice, but the tumors have regressed after another immune treatment. Similar results were then observed in mice with tumors of the breast, colon and skin (melanoma). The success is such that a clinical trial in humans – including patients with lymphoma – is currently underway.
Cancer immunotherapy is tricky. Because cancer cells are produced by the body, the immune system does not see them as a threat in the same way as viruses, for example. Some immunotherapy approaches thus rely on the stimulation of the immune system, which often involves difficult side effects. “Our approach uses a unique application of very small amounts of two agents to stimulate immune cells directly into the tumor,” says Professor Levy. “In mice, we observed amazing effects on the whole body, including the elimination of tumors throughout the animal.”
If all goes well, treatment could be used in the future on tumors before they are surgically removed, to help prevent metastasis or prevent relapse. “I do not think there is a limit to the type of tumor that we could potentially treat, as long as it has been infiltrated by the immune system,” says Dr. Levy.
You will find all the details of this study in the journal Science Translational Medicine..