CHICAGO—Breast cancer surgery without actual surgery may be possible using the same techniques used for non-surgical ablation of fibroid tumors—magnetic resonance guided focused ultrasound. That was the conclusion of a study reported here at the Radiological Society of North America Annual Meeting.
In preliminary work, researchers headed by Alessandro Napoli, MD, PhD, Assistant Professor of Radiological Sciences at Sapienza University in Rome, employed focused ultrasound to destroy breast cancer without making an incision—although the confirmation of success meant that in these early trials resection was performed to observe histologically what happened to the tumor.
“This procedure allows for the safe ablation of breast cancer,” he said at a news conference at the meeting, which had about 50,000 attendees.
Describing the procedure, he said that ultrasound is focused on small lesions as many as 70 times—literally burning the tumor to death. The treatment takes a lot longer to perform than surgery does, but the patient's recovery is much faster—a few days of edema and tenderness, and then back to normal function.
In the study, it took about two and a half hours to complete the ablation process, Napoli said. He acknowledged that with conventional surgery, a competent surgeon can perform the excision in about 20 minutes, but he predicted that once the learning curve for treatment is established, the 2.5-hour procedure will be sped up.
When pathologists examined the excised tissue in the study of 12 patients, no significant tumor was found, he reported. When the treatment is confirmed as capable of killing the tumor cells, then follow-up incision will not be necessary, he said.
Napoli explained that the basis of the technology is actually similar to what purportedly was used in 212 BC when Archimedes used mirror-focused solar energy to destroy ships blockading the port of Syracuse in Sicily. Attempts to recreate the feat since then, however, have had mixed results.
The present treatment, though, allows doctors to focus acoustic energy at a point inside the body without damaging surface tissues. “This new treatment is totally non-invasive,” Napoli said. “We are using acoustic waves that go into the body and are focused on a specific point where they destroy the tissue. We use magnetic resonance imaging to precisely target the energy for real-time control of the treatment.
“There is no incision, no puncture, no blood. This is a treatment done under conscious sedation.”
In the pilot study he reported, for women diagnosed with Stage 1 breast cancer, participants were women older than 18 diagnosed with invasive breast cancer proven by a 14- to 20-gauge core needle biopsy. They had to have had a single focal breast lesion less than two centimeters in diameter, which had to be visible to magnetic resonance imaging and in a treatable location.
The size of the tumor, at less than two centimeters or about one inch in diameter, is the point when it is most treatable, he said. In the treatment phase, the targeted tumor and healthy margins are attacked with focused ultrasound.
Women were excluded from the study if they had undergone chemotherapy within 30 days of the treatment or if they had undergone previous radiotherapy. Those who had breast implants or who had previous breast surgery and had prior surgical clips implanted were also excluded. Multiple lesions and nodal involvement are contraindications for the treatment at this time, he added.
After a treatment workup, women undergo the focused ultrasound therapy. Ten days later, the patient has another MRI scan to check for potential residual tumor and to observe destroyed tumor. Within 30 days of the procedure, the women undergo sentinel node surgery, and then undergo whole breast radiation treatment. In the pilot trial, surgery was performed 30 days after the initial therapy to assess the outcomes on the tumor.
The pathological results following surgery found that among the dead tumor tissue were “islands of tumors that appeared to be morphologically intact, but they are not viable,” Napoli said. The researchers are now investigating how these cells survived and whether they constitute a recurrence threat. He illustrated that the necrotic tissue is clearly observed from the healthy parenchyma.
The treatment in the breast with focused ultrasound follows years of use of the treatment to destroy uterine fibroids through the non-invasive technique. He suggested that a turf battle between surgeons and interventional radiologists—similar to the ongoing debate over use of focused ultrasound in treatment of uterine fibroids—could also emerge over use of the technology in breast cancer.
The researchers noted that it is difficult to recruit patients for the study because surgeons are reluctant to refer them to the new procedure. He said that the researchers will try to recruit 50 women for the initial pilot study before moving on to imaging follow-up without surgical confirmation. At present, the center has been treating about one woman every two months.
His center sees about 100 women a week, but there is a continuing problem with surgeons being reluctant to send patients to try this new technology. “The patients tend to belong to the surgeons; not the radiologist,” he said.
Napoli noted that if one looks at the history of the use of guided ultrasound in treatment of fibroids, the availability of the non-invasive treatment has actually increased the number of women who seek gynecology consults to determine if the non-invasive treatment is applicable for them. “The patients want to spare their uterus, but we can't treat all the patients with this therapy. About 80 percent of the women who seek fibroid ablation will undergo surgery,” he said.
“But we are positive about the future, because in the end it will be a patient choice. Patients tend to like to spare their organs. They like the idea that they can remove cancer without being cut open.”
It is also convenient, he emphasized. “These women undergo the procedure in the morning, and in the afternoon they can go to work, they can go home—they can do whatever they need to do.”
There are, however, several limitations in the use of focused ultrasound in treating breast cancer, he noted:
- It cannot be used to ablate tumors that are larger than 2 cm;
- The tumor has to be the only lesion in the breast;
- The tumor has to be located at least 10 mm from the skin—including a 2 mm margin of healthy breast tissue to assure negative margins.
- The tumor has to be at least 10 mm from the nipple; and
- The procedure takes substantially longer to perform than with surgery.
He noted that a similar study is under way in Japan using the focused ultrasound, but in that series there is no surgical follow-up. The patients are similarly treated with focused ultrasound and then are followed with imaging for five years.
The moderator of the news conference, Salomao Faintuch, MD, Assistant Professor of Radiology at Harvard Medical School/Beth Israel Deaconess Hospital, Boston, said that until this study he had not been aware of focused ultrasound being used in breast cancer.
“Besides resistance to change among the medical community, there is another component of this research to consider. This is very new technology. Before we use this technology as a sole method of treatment we definitely have to have a lot more results to show that outcomes with this technology are equivalent to surgery. Right now the mainstay of treatment for breast cancer is surgery, which is combined with additional treatments such as chemotherapy or radiation therapy.”