Women's own cells could blast breast cancer
The idea of using your own cells to create a vaccine seems to be the ultimate in personalized medicine, and results from a breast cancer trial bring this idea yet another step closer. After receiving just four weeks' treatment with a vaccine based on their own white blood cells, women with ductal carcinoma in situ (DCIS), an early form of breast cancer, showed an immune response, or even complete destruction of their tumors.
The vaccine, developed at the Perelman School of Medicine and the Abramson Cancer Center at the University of Pennsylvania, uses patients' dendritic cells, a type of immune cell. These were primed with HER2/neu, a protein these patients overexpress, and then the women received four shots over four weeks. At the end of the treatment, any remaining disease was removed by surgery, which is normal standard of care in DCIS.
Of the 27 women who were treated with the vaccine, 5 had no remaining tumor by the time they had surgery--around 20%--and other patients showed lower levels of HER2 protein (raised levels are linked with more aggressive forms of breast cancer). Overall, 85% of the women had an immune response against HER2, in some patients lasting more than four years. The vaccine was also safe, with low-grade side effects such as tiredness, pain at the injection site, chills and headaches.
"Previous vaccines targeted tissue antigens that were expressed on the cancer cells, but were not necessary for tumor survival. Here we're going after HER2/neu, which is critical for survival of early breast cancers. If we knock it out with the immune response, we cripple the tumor cells," says the study's leader, Brian Czerniecki of the Rena Rowan Breast Center and Abramson Cancer Center.
As shown in this study, for some women, treatments of this type could completely eradicate their tumors. However, even for those who didn't see an effect, the immune response they experienced might possibly prevent their cancers from becoming more aggressive. This study is too small to be able to say whether this is true, but a couple of years down the line, the researchers hope to have more definite news. They are enrolling patients for a larger study and plan to add HER1 and HER3 along with HER2. These types of vaccinations might also show potential in fighting melanoma and lung, brain, and colon cancers.
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