Yttrium-90 (Y-90) radioembolization is a minimally invasive treatment that may slow disease progression in breast cancer that has metastasized to the liver. It delivers cancer-killing radiation directly to the tumor, sparing healthy tissue.
A study presented at the Society of Interventional Radiology’s 39th Annual Scientific Meeting in San Diego, California, suggested that this treatment might decrease the severity of disease in patients who have no other treatment options.
Approximately 235,000 new cases of invasive breast cancer are diagnosed each year. About half of the patients who develop metastatic disease have metastasis to the liver. Many women have progressive liver disease despite multiple treatment regimens, while others do not tolerate the side effects from chemotherapy.
Y-90 radioembolization is used to treat patients with primary liver cancer and metastatic colon cancer who are not surgical candidates. Recently, its use has expanded to treatment of other secondary hepatic malignancies because it is highly effective and has low toxicity.
The procedure is a minimally invasive, image-guided therapy. An interventional radiologist inserts a catheter through a tiny incision in the groin and guides it through the blood vessels into the artery that supplies the liver. Micro beads containing the radioactive isotope are injected into the blood stream, and carried to the smaller vessels that feed the tumor, where they emit cancer-killing radiation from inside the tumor. Because Y-90 targets the tumor, radiation damage to healthy surrounding tissue is minimized.
This study examined treatment outcomes in 75 women (age 26 to 82 years) with breast cancer who underwent radioembolization of their liver metastases. The women had not responded to conventional chemotherapy and their liver metastases were too large or too numerous to treat with other modalities.
Imaging follow-up was available for 69 of the 75 women treated. The radioembolization achieved disease control in 98.5% of the liver tumors, and tumor sizes were reduced by more than 30% in 24 women. The treatment had 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,” said Robert J. Lewandowski, MD, associate professor of radiology at Northwestern University Feinberg School of Medicine in Chicago, Illinois. “The treatment is not limited by tumor size, shape, location, or number.”
Median survival for patients with more than 25% tumor burden was 278 days, and, for patients with less than 25% tumor burden, it was 119 days (P<0.0001). Patients with unilobar disease had a median survival of 928 days, while patients with bilobar disease had a median survival of 197 days (P=.0557).
“Y-90 warrants further study of its efficacy in providing supportive care to relieve patients of debilitating symptoms and control the progression of their disease,” said Lewandowski.