DUARTE, Calif. - New ways to customize therapies promise a revolution in the treatment of breast cancer and other forms of the disease, a change that has some clinicians using the word "cure."
Treatments tailored to fight not just breast cancer but each individual's specific breast cancer will result in "a disease that's controllable, treatable and curable," said Dr. Sariah Liu, an oncologist at City of Hope research hospital in the Los Angeles area.
"This is no longer a dream. The hope is really true," Liu said in a recent interview.
By analyzing cancer cells' genetic signatures and other biomarkers, today's researchers are discovering how to craft personalized immunotherapy, endocrine therapy and other targeted treatments that kill tumors but do not damage surrounding tissue.
Immunotherapies such as CAR T cell therapy can engineer the body's immune system to fight certain cancers. The system then "remembers" its new capabilities and is able to fend off any recurrence of the disease. Liu compared traditional chemotherapy with catching the bad guys in a neighborhood, and immunotherapy with improving the neighborhood's surveillance network.
Some of the results just a short time ago were still the stuff of science fiction.
"Immunotherapy can potentially cure cancer, even in the Stage 4 disease," Liu said. "I see Stage 4 lung cancer patients, Stage 4 melanoma patients, they're still alive after five years. This was not thinkable five years ago, but now it's a reality."
Continued observation of such patients over the long term - 10 to 20 years - must take place before they are declared truly cured, but Liu is optimistic, she said.
CAR T cell therapy is at the heart of a new City of Hope clinical trial that will test its effects on a certain kind of breast cancer, HER2-positive, in patients where it has spread to the brain. The hospital is enrolling subjects for the study, the first to focus on that specific patient population.
Researchers will remove immune system cells called T cells from patients, genetically engineer them to have certain proteins on their surfaces and then return them to the patients' bodies.
"Those proteins can recognize the tumor. So this is just like giving the T-cell a GPS system, so that once they have the GPS system they can direct the T-cells to the tumors and attack them," Liu said.
"The net effect is that they turn on your immune system and then push on the right button so that the immune system will be excited and will be able to recognize those tumor cells. And then they can utilize their own killing cells to kill the cancer," she said.
A unique aspect of the trial is its solution to the problem of delivering the modified T cells to brain tumors. Researchers will inject the cells locally into a patient's brain or regionally through infusion in the ventricular system, a technique City of Hope pioneered and found to be safe.
Results of the study will not be announced for years. City of Hope has 16 ongoing clinical trials involving CAR T cell therapy and has treated more than 200 patients using the method.
Working at a research hospital where such options are available makes it "really exciting to be a medical oncologist these days," Liu said.
"I cannot imagine how I can practice oncology without the support of the scientists and the research, because patients eventually will exhaust all standard care. If there were nothing to offer them, I would feel really bad because I'm not really able to help them when they really need me," she said.
"We're working together to make this cancer a diagnosis of the past."