Immune System Dysfunction Pinpointed in Melanoma Cases

MONDAY, May 14 (HealthDay News) -- U.S. researchers say they've spotted a key immune system dysfunction in patients with melanoma skin cancer.

A team at Stanford University School of Medicine, in California, found that the immune cells in most melanoma patients fail to respond properly to a molecule called interferon, which normally activates the immune system. This failure to respond to interferon means that the immune cells don't fight off melanoma.

The findings, published in the May issue of the journalPublic Library of Science-Medicine, could help in the development of new treatments for melanoma.

Melanoma will kill about 16 percent of the 47,700 people in the United States expected to be diagnosed with this form of skin cancer this year.

These findings help explain why a common melanoma treatment involving prolonged exposure to interferon sometimes helps melanoma patients, said senior author Dr. Peter Lee, associate professor of medicine.

"Doctors knew it worked in some people but didn't know why," Lee said in a prepared statement. This study suggests that prolonged interferon treatment may work by overcoming the immune system's inability to respond to interferon.

Previous research has found that cancer patients often have immune system problems, but, until now, scientists didn't know which genes or pathways were at the root of the trouble. Identification of this interferon response disruption may boost efforts to develop vaccines for different types of cancer, the Stanford researchers said.

"We think this is a dominant way that immune dysfunction occurs in people with cancer," Lee said.

More information

The U.S. National Cancer Institute has more about melanoma.

SOURCE: Stanford University, news release, May 7, 2007