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Embolization Remains Good Option for Unresectable Liver Cancer

January 24, 2009 — New research into transarterial chemoembolization, or the vascular delivery of chemotherapy to the liver using microspheres, shows promising results for patients with unresectable hepatocellular carcinoma, according to 2 small studies presented at the 21st annual International Symposium on Endovascular Therapy (ISET), held in Hollywood, Florida.

A third small study that used embolization without chemotherapy in this patient population also showed promising early results.

The studies represent the ongoing efforts of researchers and medical-device companies to improve or refine approaches to embolization. Although surgery is the most effective way to treat hepatocellular carcinoma, more than two thirds of liver cancer patients are not candidates for surgery because of the size or location of the tumor, or because the tumor has grown into the blood vessels. Embolization typically is not curative but slows disease progression. However, according to a statement from ISET, improvements in miscrospheres are making them more effective.

An Expanding Microsphere
In a multicenter Italian trial of 53 patients with liver cancer, investigators used HepaSphere beads (BioSphere Medical, Rockland, Massachusetts) loaded with chemotherapeutic agents. The beads expand after lodging in the arteries that feed the tumor, and blood flow is theoretically more effectively blocked. The microspheres release chemotherapy directly into the tumor, according to a statement. HepaSphere beads are the only expanding microspheres and are not currently available in the United States.

A month after treatment, 27 of the patients (51%) showed a complete response, 18 (34%) showed a partial response, and 8 (15%) showed stable disease.

Complete response was defined as complete vital tumor tissue disappearance and absence of new lesions. Partial response was a decrease of 50% or more of the vital tumor tissue.

Six months later, 34 patients remained, 3 died, 4 were lost at follow-up, and 12 received other treatments. Of the remaining patients, 19 of the 34 (55.9%) had complete tumor response, 8 (23.5%) had a partial response, and 7 (20.5%) had disease progression.

Postembolization syndrome, which consists of fever, pain, and nausea, occurred in 14 of the 53 patients (26.4%).

"Patients who still had good liver function and who had tumors in only 1 lobe of the liver did better with this treatment," said Maurizio Grosso, MD, chair of the Department of Radiology at Santa Croce and Carle Hospital, in Cuneo, Italy, in a statement. "We're hopeful that treatment with HepaSphere will be an improvement over traditional chemoembolization."

Doxorubicin-Emitting Beads Superior
In a study at St. Joseph's Hospital and Medical Center, in Tampa, Florida, researchers compared microspheres emitting doxorubicin with those emitting irinotecan in patients who had colorectal cancer that had metastasized to the liver and in patients with primary liver cancer.

"Colorectal metastasis and primary malignant hepatic neoplasms have a poor prognosis with dismal survival rates of 31% at 1 year and 26% at 2 years," explained the study authors, led by Glenn Stambo, MD, vascular and interventional radiologist at St. Joseph's.

In the study, patients with primary liver cancer (n = 11) received beads that emitted doxorubicin. Of the patients with colorectal cancer and a related liver cancer (n = 25), 13 received doxorubicin-emitting beads and 12 received irinotecan-emitting beads. All of the microspheres were LC Beads (AngioDynamics, Queensbury, New York).

At 2 years, the patients who received the doxorubicin-emitting beads had superior mortality outcomes; 10 of 11 (91%) of the primary liver cancer patients and 10 of 13 (77%) of the colorectal patients were still alive. Only 1 of 12 (8.3%) of the irinotecan patients was alive after 2 years.

Researchers are studying why doxorubicin seemingly works better in these patients.

"There is definitely a chance of cancer cure with this procedure, beyond just palliation," said Dr. Stambo in a statement. "The more isolated the tumor and its blood vessel feeders, the better the chance for a complete cure."

Embolization Without Chemotherapy
Matching bead size with blood vessel size in the liver was the focus of an Italian study in which embolization without chemotherapy was used in the treatment of 25 patients with liver cancer.

Vessels within a liver tumor range of 20 to 120 µm and should be the target for achieving ischemia and necrosis with embolization, said principal investigator Franco Orsi, MD, chief of interventional radiology at the European Institute of Oncology, in Milan, Italy, in a poster presented at the meeting.

The bigger the microspheres used, the further from the tumor the embolization will be, Dr. Orsi and his coauthors noted.

To address these concerns, the researchers used 40 and/or 100 µm Embozene microspheres (CeloNova BioSciences, Newnan, Georgia) to embolize 34 target liver lesions in the 25 patients.

After 1 month follow-up, 18 tumors (52%) had shrunk in size, and 16 (48%) remained stable with no tumor growth detected. In a group of 16 tumors with a follow-up ranging from 6 to 12 months, 2 tumors (13%) completely disappeared, 7 (44%) continued to shrink, 2 (12%) were stable, and 5 (31%) grew. To date, 14 patients have had more than 1 year of follow-up care, with a 93% survival rate.

Dr. Orsi and colleagues emphasized that pulmonary shunting must be carefully excluded when 40 µm particles are used, and recommended performing Tc-99 macro-aggregated albumin liver perfusion scintigraphy in all patients.

The researchers have disclosed no relevant financial relationships.

21st Annual International Symposium on Endovascular Therapy (ISET): Abstracts 8, 125, 126. Presented January 19 and 20, 2009.