Using tiny chemotherapy-soaked beads to choke off and kill cancerous liver tumors is becoming more successful, according to research being presented at the 21st annual International Symposium on Endovascular Therapy (ISET).
Transarterial chemoembolization (TACE) is a minimally invasive therapy that takes a two-pronged approach to treating cancer. Interventional physicians use minimally invasive methods to deliver the beads (also called microspheres) to the blood vessels that feed the tumor. The beads are combined with cancer-killing chemotherapeutic agents and then delivered to the blood vessels. The beads lodge in the blood vessels, blocking blood flow to the artery and cutting off the blood supply to the tumor - known as embolization. Several studies being presented at ISET report on advances in the treatment.
The most effective way to treat most cancerous tumors is by surgically removing them. However, more than two-thirds of people with liver cancer aren't candidates for surgery due to the size or location of the tumor, or because the tumor has grown into the blood vessels. Doctors have turned to other methods of treatment, including TACE. Because the chemotherapy is delivered directly to the tumor - rather than to the entire body as is the case with traditional chemotherapy - side effects usually are lessened.
On average, only about one in four liver cancer patients is alive after two years. Although TACE typically is used to slow the disease, not cure it, improvements in the beads are making it more effective and promising as a cure in some cases. Improvements include beads that absorb the chemotherapeutic agent (rather than just being mixed with it), and then release the drug once in the body, as well as modifications to uniformity and size of the beads themselves so that they can more fully block the blood vessel and further guard against potential leakage of blood that could feed the tumor.
More than 21,000 people are diagnosed with liver and bile duct cancer, and more than 18,000 will die of the disease each year, according to the American Cancer Society.
Hope for People with Liver Cancer
A study at St. Joseph's Hospital and Medical Center in Tampa, Fla., included 25 patients who had colorectal cancer that had spread to the liver and 11 with primary liver cancer. All of the patients with primary liver cancer received LC Beads(TM) that emitted doxorubicin, a type of chemotherapeutic agent, while 13 of the colorectal patients received doxorubicin-emitting beads and 12 received beads that emitted irinotecan, another chemotherapeutic agent. The patients who received the doxorubicin-eluting beads fared better - 10 of 11 (91 percent) of the primary liver cancer patients and 10 of the 13 (77 percent) of the colorectal patients were alive after two years. Conversely, one of 12 (8.3 percent) of the irinotecan patients were alive after two years. Researchers are studying why doxorubicin appears to work better in these cases.
LC Beads slowly elute the chemotherapuetic agent over the course of two weeks, providing a constant dose of the drug to the tumor, without leading to systemic side effects.
"There is definitely a chance of cancer cure with this procedure beyond just palliation," said Glenn Stambo, M.D., vascular and interventional radiologist at St. Joseph's Hospital and Medical Center. "The more isolated the tumor and its blood vessel feeders, the better the chance for a complete cure."
Improvements in Chemoembolization
A multicenter Italian trial used HepaSphere(TM) beads loaded with chemotherapeutic agents to deliver treatment to 53 patients with liver cancer. HepaSpheres are designed to expand after they lodge in the arteries that feed the tumor, so that blood flow is more effectively blocked; these microspheres absorb the chemotherapeutic agent, and then the drug is released directly into the tumor.
A month after treatment, tumors in 27 of the patients (51 percent) showed a complete response, 18 (34 percent) showed a partial response and eight (15 percent) showed stable disease. Six months later 19 of 34 patients (55.9 percent) had complete tumor response, eight (23.5 percent) had a partial response and seven (20.5 percent) had growing disease. Of the remaining 19 patients, three died, four were lost at follow-up and 12 receive other treatments.
"Patients who still had good liver function and who had tumors in only one lobe of the liver did better with this treatment," said Maurizio Grosso, M.D., chairman of the Department of Radiology at Santa Croce & Carle Hospital, Cuneo, Italy. "We're hopeful that treatment with HepaSphere will be an improvement over traditional chemoembolization."
Embolization without Chemotherapy
Researchers at the European Institute of Oncology in Milan, Italy, are studying using embolization without the chemotherapy for liver cancer. The study included 25 patients with 34 primary liver tumors. All patients received Embozene(TM) microspheres alone, without the addition of any chemotherapeutic agents in the beads. The patients had 35 sessions with the microspheres. After one month follow-up, 18 tumors (52 percent) had shrunk in size while 16 (48 percent) were the same size with no tumor growth detected. In a group of 16 tumors with a follow up ranging between six and 12 months, two tumors (12 percent) completely disappeared, seven tumors (44 percent) continued to shrink, two (12 percent) were stable and five (31 percent) grew, although they were still of a size suitable for new local treatments. To date, 14 patients have had more than one year of follow-up care and 93 percent of them are still alive.
"One concern with embolization is that blocking the tumor feeding vessels in some cases leads to restriction in blood flow and cell death," said Franco Orsi, M.D., chief of interventional radiology at the European Institute of Oncology. "One of the main benefits of Embozene microspheres is the precise, well-calibrated sizing, which match the small blood vessels that feed the tumors. The larger the particles used, the further away the embolization from the tumor and the less effective the treatment will be. Moreover, embolization without drugs usually causes few or no post-treatment side effects and patient can usually be discharged the next day."
Dr. Orsi notes that another very important feature of this new material is its ability to prevent inflammatory reactions, which is one of the leading causes of tumor growth.
Considered to be the premier meeting on endovascular therapy, the International Symposium on Endovascular Therapy (ISET) is attended by more than 1,200 physicians, scientists, allied health professionals and industry professionals from around the world. The meeting pioneered the use of live cases to promote the multidisciplinary treatment of cardiac and vascular disease by endovascular means. ISET is presented by the Baptist Cardiac & Vascular Institute, Miami. ISET 2009 is taking place Jan. 18-22 near Miami Beach, Fla. For more information, visit www.ISET.org