But, so far, the therapy is experimental and has only been shown to work in a few patients, albeit with minimal side effects.
"It's a very labor-intensive procedure," said Dr. Warren Chow, associate professor of medical oncology at City of Hope Cancer Center in Duarte, Calif. "It's not going to be something that a lot of people are going to be able to do [right away]."
The technique used in the second study was similar to that demonstrated in the Rosenberg study.
Here, the researchers genetically engineered human immune cells to target two cancer-related proteins on cancer cells, then injected these cells into mice with human melanomas.
The proteins seem to belong to a subgroup of tumor cells that are somehow more significant in making melanoma more lethal.
"They're targeting the cancer stem cell, which is becoming very popular now," Chow said.
Most of the tumors shrank and stayed that way for up to 36 weeks. The method still needs to be tested in humans. And studies that start with animals often fail to produce desired results in people.
The immune treatments certainly make sense, said Dr. Edibaldo Silva, an associate professor of surgical oncology at the University of Nebraska Medical Center in Omaha.
And, in a way, any news is good news for a cancer like melanoma that has such a dismal prognosis. Interferon, which has been used for 20 years, has awful side effects even though it prolongs life.
"You live one year longer, but you're miserable from side effects," Silva said. "The medical community has been disheartened."
The U.S. National Cancer Institute has more on metastatic cancer.
SOURCES: Steven A. Rosenberg, M.D., Ph.D., chief, surge
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