A new interventional radiology treatment that utilizes intra-arterial yttrium-90 (Y-90) microspheres may prolong the lives of many patients with hepatocellular carcinoma. New data presented at the Society of Interventional Radiology's 35th annual scientific meeting showed this approach may extend life for the more than three fourths of hepatocellular carcinoma patients who are not eligible for surgery.
"This is encouraging news for liver cancer patients, especially those who have blockage in the portal vein. While patients aren't cured, their lives are being extended and their quality of life is improving with Y-90 microsphere treatment," said study investigator Riad Salem, MD, MBA, who is director of interventional oncology at North\western Memorial Hospital, Chicago. "This is a unique interventional radiology treatment, which combines the radioactive isotope Y-90 into microspheres that deliver radiation directly to a tumor. It is a particularly elegant way to give patients a cancer treatment that doesn't harm the healthy cells. Patients don't feel sick or have any of the side effects that happen with standard cancer treatments."
Combining the radioactive isotope Y-90 into microspheres to deliver radiation directly to a tumor allows for a higher, local dose of radiation to be used without subjecting healthy tissue in the body to the radiation. Each microsphere is about the size of five red blood cells in width. These beads are injected through a catheter from the groin into the liver artery supplying the tumor. The beads become lodged within the tumor vessels, where they exert their local radiation, causing cell death. Y-90 radiates from within and, because it is administered via the hepatic artery, it can be viewed as "internal" radiation, Salem explained. Y-90 treatment is approved by the US Food and Drug Administration for the treatment of unresectable hepatocellular carcinoma.
He presented data from a study involving 291 patients with hepatocellular carcinoma, all of whom were treated with intra-arterial Y-90 microspheres as part of a single-center prospective study. The researchers administered 526 Y-90 treatments (average, 1.8 per patient). They reviewed 1250 scans to assess response and time to progression. Survival by stage also was assessed. Overall, time to progression was 7.9 months. Salem said that, in oncologic standards for this disease, these were extremely promising findings.
The survival times differed by the cancer staging system used: Child-Pugh A (17.2 months), Child-Pugh B (7.7 months), and Barcelona Clinic Liver Cancer staging (A, 26.9 months; B, 17.2 months). Toxicities included fatigue (57%), transient pain (23%), nausea/vomiting (20%), and bilirubin toxicity (5%).
"We take the approach that this is definitive therapy," said Salem in an interview with The Oncology Pharmacist. "The trend is to move away from external beam and move to this kind of therapy for the liver, given the significant advantages and the limitations of external beam."
He noted that liver cancer treatment options are limited. Although surgical removal of liver tumors offers the best cancer for a cure, it is not possible for more than three fourths of primary liver cancer patients. Liver tumors are often inoperable because the tumor may be too large or may have grown into major blood vessels or other vital structures. Sometimes many small tumors are spread throughout the liver, making surgery too risky or impractical, Salem explained. Historically, chemotherapy drugs and external radiation therapy have been ineffective at curing inoperable liver cancer.
"These are early promising results. This information can be used to design future Y-90 trials and to describe Y-90 as a potential treatment option to liver cancer patients," Salem said. He noted that this approach adds to interventional radiology's nonsurgical advances for liver cancer, which in clude delivering chemotherapy directly to the affected organ (chemo embolization), killing the tumor with heat (radiofrequency ablation), or freezing the tumor (cryoablation) to treat cancer locally.