New Breast Cancer Trial Starting

The UCSF Carol Franc Buck Breast Cancer Center will test a drug therapy those blocks the formation of new blood vessels to prevent cancer cells from growing and spreading to other parts of the body.

The process by which new blood vessels form is called angiogenesis. Cancer cells make a protein that stimulates the growth of new blood vessels in nearby endothelial cells. These new blood vessels essentially feed the cancer cells with oxygen and nutrients, helping the cells to grow, invade nearby tissue and spread throughout the body, explained Hope Rugo, M.D., principal investigator of the study and UCSF associate clinical professor of medicine. Solid tumors cannot grow beyond the size of a pinhead without the formation of new blood vessels, according to the National Cancer Institute (NCI). The purpose of the UCSF trial is to see if an antibody, used in combination with chemotherapy, can prevent new blood vessels from forming, cutting off the tumorís supply of oxygen and nutrients. "The idea is that new blood vessel growth is part of the mechanism cancer cells use to create their own survival advantage", Rugo said. "Cancer cells canít grow properly unless they have blood supply, and when we find more blood vessels in a particular cancer, it appears to correlate with a worse outcome."

About 15 proteins are known to activate angiogenesis, according to NCI, including vascular endothelial growth factor (VEGF). UCSF is one of 100 sites participating in this randomized trial that is testing a drug that targets VEGF. The antibody, called rhuMAb-VEGF, will be given in combination with Xeloda; a powerful oral chemotherapy agent effective in the treatment of advanced breast cancer. South San Francisco-based Genentech developed the antibody and is sponsoring the study.

Breast cancer is the most common malignancy in U.S. women, and 182,000 women will be diagnosed with invasive breast cancer this year, and 43,000 women will die of the disease, according to the American Cancer Society. Despite improvements made in treating early stage breast cancer, many women with initially localized disease relapse and eventually die of metastatic disease. Metastatic disease, when the cancer has spread to other parts of the body by the blood or lymph system, is generally not curable with current therapy.

The study is enrolling 400 women nationwide with advanced breast cancer who have progressed after one or two prior chemotherapy regimens. Participants will be randomized to receive either the combination of Xeloda and rhuMAb-VEGF or Xeloda alone. The antibody is given intravenously every three weeks. Xeloda is given by mouth. Treatment is continued until the cancer begins to grow. While this trial is testing the effects of an anti-angiogenesis therapy in women with metastatic disease, the ultimate goal is to determine whether this approach could be effective in women with earlier stages of breast cancer. "If it works in women with advanced cancer by prolonging the time until their disease progresses, we will immediately move it into maintenance and treatment of curable cancers", Rugo said.

For more information about the trial, call Heather Terry; study co-ordinator at the UCSF Breast Cancer Center, (415)885-7318.