Surgery, radiation therapy, chemotherapy: These are some of the most common treatment plans for breast and other types of cancer. But they can often be invasive, damaging healthy tissues alongside cancerous ones.
Now, researchers and clinicians at the University of Virginia are one step closer to offering a new treatment option for breast cancer that would bypass the often toxic side effects of more traditional cancer treatments.
Multiple clinical trials at UVa are currently examining the addition of focused ultrasound therapy — the application of highly focused sound waves — to existing immunotherapy treatments. Immunotherapy harnesses the body’s immune response to fight off invasive tumors.
But immunotherapy doesn’t work for all kinds of tumors, especially breast cancers. Focused ultrasound could greatly expand the types of tumor that respond to immunotherapy, according to Natasha Sheybani, research director of the UVa Focused Ultrasound Cancer Immunotherapy Center, the first such center in the world.
“I would liken [focused ultrasound] to the concept of taking a magnifying glass out on a hot day and basically shining a bunch of rays of light through the glass such that you can burn a hole in a leaf,” Sheybani said in a UVa Lifetime Learning webinar Thursday. “You’ve projected all of that energy into a single focus. We’re doing the same thing with sound waves here.”
This process allows focused ultrasound to not only be highly precise in targeting tumors, but completely safe and noninvasive. And, once applied to a site, it could have beneficial “local immune response,” harnessing the body’s immune system to fight the cancer, Sheybani said.
In Sheybani’s lab, researchers have applied focused ultrasound to tumors to “cook,” or heat up cancer cells in the breast to the point of destruction, a process called ablation. In mice, focused ultrasound combined with gemcitabine — a type of chemotherapy — has been shown to increase immune system response to attack the cancer. The combined treatment has reduced tumor burden and extended survivorship to a greater degree than the chemotherapy or focused ultrasound alone.
A new UVa clinical trial aims to examine the use of focused ultrasound in combination with gemcitabine to treat patients with early stage breast cancer. The study is currently open and accruing, having treated five patients already.
The study is the third in a three-step approach to determining focused ultrasound, in combination with other therapies, as an effective treatment for breast cancer, according to David Brenin, chief of the Division of Breast and Melanoma Surgical Services at UVa.
The first study targeted fibroadenoma, a type of breast tumor that is “benign, but bothersome,” Brenin said. Unlike surgical removal, which would result in a scar, focused ultrasound can effectively target the tumor in only a few hours and without the use of anesthesia.
The first 20 patients exhibited a 69% reduction in tumor volume, Brenin said. The clinical trial expanded enrollment, and the treatment is now “on the cusp” of Food and Drug Administration approval, Brenin said.
The next step was treating stage 4 breast cancer with focused ultrasound and pembrolizumab, a type of immunotherapy.
“We know that pembrolizumab is able to induce an immune response in some breast tumors but not most,” Brenin said during the Thursday webinar. “We also know that focused ultrasound ablation is able to induce an immune response in most tumors, but that local immune response is typically not enough on its own to be curative.”
But combined, the two treatments could be more effective in treating stage 4 breast cancer. And according to Brenin, the preliminary results are “intriguing.”
Sheybani said her lab’s ultimate goal is to be more precise in cancer treatments, which often take a “one-size-fits-all approach.” Focused ultrasound, combined with the “constellation of different immunotherapies” available, would help them do just that.