STANFORD, Calif. -- Researchers at the Stanford University School of Medicine have begun to shed light on why the human immune system isn't able to stop such cancers as melanoma, suggesting answers that could pave the way for better treatment of this often-fatal illness.
In a small study, the scientists found that the immune cells in a majority of people with this deadly skin cancer fail to respond properly to a molecule called interferon, which normally activates the immune system. Without the ability to respond to interferon, the cells are less able to fend off the cancer, according to the study that will be published in the May issue of Public Library of Science-Medicine.
These results help explain a decade of research showing that people with cancer often have dysfunctional immune systems. Until now, researchers could tell that the immune system wasn't working properly but didn't know which genes or pathways were involved in that failure. Finding the disruption in the cancer cells' interferon response could help in the development of vaccines to treat cancers.
"We think this is a dominant way that immune dysfunction occurs in people with cancer," said senior author Peter Lee, MD, associate professor of medicine.
Lee was interested in melanoma rather than other forms of cancer in part because of the deadly nature of the disease, which will kill about one in six of the 47,700 people it is expected to strike this year. Unless melanoma is caught early and removed, there is no effective treatment, although research groups have been testing vaccine therapies for the disease. However, Lee worried that unless researchers better understood immune dysfunctions in those people, the vaccines would have a low probability of success. "If you don't address the underlying immune defects, then vaccines won't do any good," Lee said.