The treatment is called yttrium 90 (Y-90) radioembolization. Doctors insert a catheter through a tiny cut in the groin and guide it into the artery that supplies the liver. Radiation-emitting micro beads are then sent through the catheter and float out to kill small blood vessels that feed the tumor.
Researchers led by Dr. Robert Lewandowski, an associate professor of radiology at Northwestern University Feinberg School of Medicine in Chicago, looked at the outcomes of 75 patients. The women ranged in age from 26 to 82, and had chemotherapy-resistant breast cancer that had spread to the liver ("metastatic" disease). Their liver tumors were too large or too numerous to be treated with other methods, the authors noted.
Y-90 radioembolization therapy stabilized 98.5 percent of the treated liver tumors, according to the study, which was to be presented Monday in San Diego at the annual meeting of the Society of Interventional Radiology.
In addition, 24 of the women experienced a more than 30 percent shrinkage in tumor size after treatment, which caused few side effects.
"Although this is not a cure, Y-90 radioembolization can shrink liver tumors, relieve painful symptoms, improve the quality of life and potentially extend survival," Lewandowski said in a society news release.
"While patient selection is important, the therapy is not limited by tumor size, shape, location or number, and it can ease the severity of disease in patients who cannot be treated effectively with other approaches," he added.
Two breast cancer experts were cautiously optimistic about the findings.
According to Dr. Neelima Denduluri, "while these results appear promising, this is a very small retrospective study," meaning that it fell short of the "gold standard" type of prospective trial that tracks patients going forward over time. "Randomized controlled prospective studies addressing this issue are necessary before radioembolization can be incorporated routinely," she believes.
For now, "in women that cannot receive systemic therapy due to toxicities [side effects], are not eligible for clinical trials that utilize new agents, or have exhausted conventional chemotherapy options, radioembolization may be a choice," said Denduluri, a medical oncologist with Virginia Cancer Specialists in Arlington, Va., a US Oncology Network affiliate.
Dr. Stephanie Bernik is chief of surgical oncology at Lenox Hill Hospital in New York City. She said that while this type of therapy has been used to fight liver tumors, "the ability to use this therapy in treatment of metastatic breast cancer to the liver offers some hope to patients with the disease."
Bernik stressed that, right now, the treatment can only extend survival for women with advanced breast cancer, it is not a cure. However, "as the technique is modified and perfected, it is hoped the [treatment] can help achieve remission in women with advanced disease."
Each year in the United States, about 117,000 patients are diagnosed with breast cancer that has spread to the liver. Chemotherapy is the standard treatment in such cases, but is not effective in, or suitable for, all patients.
Experts note that studies presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
The U.S. National Cancer Institute has more about liver cancer.