NewsMax.com Wires
May 14, 2001

SAN FRANCISCO -- Two new experimental vaccines that help stimulate an immune response to fight cancer cells are showing promise in cancer patients who have failed other treatments according to study results presented Sunday at the conference of the American Society of Clinical Oncologists.

Researchers at Stanford University used a two-step process to boost the immune systems of colorectal and lung cancer patients. First, the scientists extracted dendritic cells - rare cells that guide the immune system - from patients and then boosted their number using a specialized drug. Once extracted and multiplied, the researchers genetically altered them to display a cancer-associated protein.

When the cells were reintroduced back into the patients, they caused an immune response that attacked cancer cells. Three of the 12 patients studied exhibited clinical improvement. All of them were colorectal cancer patients.

Unlike chemotherapy, there were no significant side effects associated with the treatment.

"We do not know if the patient who remains cancer free will staying remission, but having results like this with immune therapy in colorectal cancer has not been seen before," said Dr. Lawrence Fong, a researcher at Stanford Medical Center and the study's lead author.

A second promising vaccine therapy targets cancerous tumors by genetically engineering the tumor to attack itself.

Researchers altered the tumor to secrete a kind of protein that stimulates the immune system to fight off the cancer. The patient's own tumors are harvested, engineered and then reintroduced into their bodies.

A study of 80 patients with non-small-cell lung cancer is still under way and only 11 subjects have completed the full treatment. But the results from the first round of patients look hopeful. In three of the 11 patients with advanced-stage disease, the cancer completely disappeared and has not recurred in nine months.

"These findings are all the more noteworthy given that lung cancer patients who fail chemotherapy have little chance of responding to further chemotherapy or other treatment," said Dr. John Nemunaitis, a University of Pennsylvania oncologist and lead researcher of the study.

Copyright 2001 by United Press International.

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