The goal of the research is to prevent breast cancer recurrence in women who've already experienced remission of the disease. In cases where cancer has spread outside the breast, the 10-year relapse rate can be as high as 90 percent.
Mayo Clinic researchers -- collaborating with colleagues at the University of Washington -- showed that their experimental therapy to remove the block did not harm the immune system -- in fact, it boosted it. Mice that received the toxic injections that killed the immune system blockages had tumors that were one-tenth the size of mice that did not receive the injections.
Breast cancer researchers have known for years that the body's immune system is naturally poised to reject breast cancer -- but in breast cancer patients, something interferes with this rejection, allowing the cancer to grow unchecked. This new finding helps unlock that mystery and may lead to safer, gentler therapies.
"Evidence is emerging that some of the effects of chemotherapy are due to depleting T-regulatory (T-reg) cells," says Keith Knutson, Ph.D., the Mayo Clinic immunology researcher who led the study. "The strategy we use in our investigation may actually be a way to target the T-regs directly, without using the indirect route of chemotherapy. Depleting T-regulatory cells may boost natural immunity against breast cancer."
Significance of the Research
The Mayo Clinic and University of Washington collaborative study is the first to show these two new important aspects of breast cance