American researchers this week are announcing an improved breast cancer vaccine that could have the potential to destroy tumors. The findings, which are reported in the journal Cancer Research, are based on the new vaccine which delivers a cancer-fighting gene into cells, which then produce immune system proteins as well as tumor-destroying cells. “In our own mind it is a very significant advance because we have put the gene into the cells in the body. The vaccine is produced by your own cells. It is made right in your body,” said Wei-Zen Wei of Wayne State University in Detroit, who led the study. The vaccine eliminated tumors in mice from a type of cancer called HER2 positive cancer. HER2-positive cancers account for between 20 percent and 30 percent of breast cancers. The vaccine even worked to eliminate HER2 tumors that had developed resistance to drugs designed to fight them, the report said. The HER2/neu protein is over-expressed, meaning it is over-active, in several tumors including breast, colorectal and ovarian cancer. Herceptin, also known as trastuzumab, an expensive antibody-based drug made by Genentech Inc, can treat these tumors. But many patients eventually acquire what is known as resistance and the tumors start growing again. Breast cancer is the top cause of cancer death among women worldwide, with 1.3 million new cases diagnosed annually and 465,000 deaths, according to the American Cancer Society.
