One type of cancer therapy that offers great promise is immunotherapy, a technique that harnesses the power of the immune system to recognize and attack cancer cells. Medical oncologist Clifford Hudis says that new breast cancer therapies may depend on our ability to expose novel targets and enhance parts of the immune system that may be useful in fighting cancer cells.
T cells, which play a central role in the function of the immune system, have the ability to identify and kill cancer cells. However, the body produces also substances such as CTLA-4 to prevent the body from making too many T cells. Breast cancer expert Larry Norton says scientists are currently evaluating the effectiveness of a drug called ipilimumab, an antibody that blocks CTLA-4, to unleash T cells on breast cancer cells.
Researchers are also investigating a method of increasing T cell production that uses cryoablation. In this technique, tumor cells are frozen, and as the cells thaw they release CTLA-4, which can then be targeted with ipilimumab, giving T cells the green light to attack cancer cells.
Along with Memorial Sloan Kettering scientists, medical oncologist Elizabeth Comen is evaluating yet another approach in which doctors may one day be able to remove a patient’s neutrophils (a type of white blood cell), increase their cancer-fighting capacity with growth factors, and later reintroduce them back into the patient.