MONDAY, April 4, 2005 (HealthDay News) -- The phrase "we can't operate" may sound like a death knell to many cancer patients, particularly the hundreds of thousands of Americans diagnosed each year with lung or liver malignancies.
But two new technologies could re-open the door to hope for many of them.
For the more than 100,000 U.S. patients facing inoperable primary or metastatic liver cancers each year, a technique called chemoembolization may extend survival for at least six years, a new study finds.
And for patients with the nation's No. 1 cancer killer, lung cancer, researchers say a minimally invasive heated probe was successful in eradicating inoperable tumors in 93 percent of cases.
That technique, called radiofrequency ablation, "is creating a new chapter in oncology," said lead researcher and interventional radiologist Dr. Riccardo Lencioni, of the University of Pisa, in Italy.
He presented his team's findings over the weekend at the annual scientific meeting of the Society of Interventional Radiology, in New Orleans.
Radiofrequency ablation involves the insertion of a heated needle through the chest wall directly into the tumor site, effectively "cooking" the malignancy.
"The treatment has been shown to be successful in treating tumors in the liver," Lencioni noted, but its value against other cancers was less known.
In their study, the Italian team used the technique on 106 patients with a total of 186 malignant, inoperable tumors measuring 3.5 centimeters in diameter or smaller.
"Radiofrequency ablation resulted in impressive two-year cancer-specific survival in these patients who were rejected from surgery," Lencioni said.
In fact, 91 percent of patients in the study were still alive two years after this intervention, the researchers report. Complications linked to the procedure were minimal and easily managed, Lencioni added.
He stressed that surgery "must still be the first option" for lung cancer patients whenever it is feasible. However, because of late detection and/or poor cardiovascular health, surgery is often out of the question for many patients, he said.
The very best candidates for this "hot needle" treatment are "patients with early-stage, limited disease," according to Lencioni. "Whether radiofrequency ablation could be used to also treat patients with more advanced tumors is not defined yet," he said.
Inoperable liver cancer is another chilling diagnosis, because in the majority of cases, the malignancy has migrated to the liver from another organ.
According to the American Cancer Society, about 22,000 cases of "primary" liver cancer originate within the organ itself, but up to 100,000 U.S. patients each year develop secondary, metastatic tumors in their livers after battling cancer in other body sites.
More often than not, detection comes too late for surgery, said researcher Dr. Jeff Geschwind of Johns Hopkins University School of Medicine.
For these patients, systemic chemotherapy -- with its often painful side effects -- is the only treatment available.
"A lot of these patients present with far-advanced disease and they have no other options," Geschwind said.
His team of researchers hopes to change that scenario, however.
Presenting the findings April 4 at the radiology meeting, Geschwind said the study involved 149 liver cancer patients with inoperable tumors treated with a new technique called chemoembolization.
"This involves the delivery of highly concentrated chemotherapy suspended in an oily medium," Geschwind explained. At the same time, doctors use tiny "microspheres" as emboli -- blocking agents -- to temporarily prevent the tumor from getting its full blood supply.
The technique capitalizes on the unique circulation of the liver. "Normal, healthy liver tissue is mostly supported by the portal vein," Geschwind explained, whereas liver tumors are typically supplied by arteries. "By using a major artery as a 'boulevard' or roadway to the tumor, we can exploit that property and hit the tumor where it hurts the most," he added.
The study suggests these tough-to-treat tumors were hit hard by the therapy.
"In our data, we've shown an extended mean survival of about six years, when otherwise patients usually only survive without treatment for maybe one year at most," Geschwind said.
In the past, he added, oncologists have been reluctant to use chemoembolization in cases where the liver tumor had involved or closed off the portal vein.
"However, what we found is that not only was it not dangerous" when performed in cases of portal vein involvement, he said, "it actually prolonged these patient's lives significantly."
Because it is so localized, chemoembolization is also much easier on patients than systemic chemotherapy, which affects tissues throughout the body. "We really have the ability to target the tumor while preserving healthy tissue," the researcher said.
The technology is making inroads in the United States, and is now available at most academic medical centers.
"I think we're on the cusp of something even bigger," Geschwind added, "because now we have at our disposal new drugs that can be even more cancer-specific."
"Unfortunately, many patients and many primary-care physicians don't yet know about the success of this therapy," he said. "I'm not saying it's a cure for liver cancer, but when you see the results in terms of prolongation of life, it's quite significant."
Lencioni agreed that radiofrequency ablation for lung tumors is also beginning to catch on in the United States, especially at large teaching hospitals. Still, he said, "many more doctors need to be trained to have the procedure widely available."
For more on these and other non-surgical breakthroughs in cancer care, visit the Society of Interventional Radiology.