FDA Clears New Device to Check Margins During Breast Cancer Surgery

Zosia Chustecka

January 02, 2013

A device for use during breast cancer surgery to check if margins are clear of cancer has been approved in the United States by the US Food and Drug Administration. The product has been available in Europe since 2008.

The MarginProbe system.

The new device, MarginProbe (Dune Medical Devices Inc), consists of a single-use probe that analyzes breast tissue removed during a lumpectomy. Using radiofrequency spectroscopy, the probe analyzes "electromagnetic signatures" at the margins of the surgically removed breast tissue and compares them to an internal library of signatures taken from both healthy and cancerous tissue. Within the space of 5 minutes, the probe provides an assessment of the excised tissue, indicating whether or not it is cancerous.

If cancer is found, the surgeon can then remove more tissue in the same procedure, which reduces the need for repeat surgery.

The device costs around $2000, according to a company spokesperson.

Results from a pivotal clinical trial in 664 women who underwent a lumpectomy showed that the new device was 3 times more effective in finding cancer in the margins when compared with traditional intraoperative imaging and palpation assessment, according to the manufacturer. The data also showed a significant reduction in the need for re-excision when the probe was used.

This device offers "a refinement" to lumpectomy, commented Freya Schnabel, MD, who is one of the investigators involved in the trial and is director of breast surgery at the New York University Langone Medical Center in New York City. It improves the efficiency of this technique and reduces the burden of re-excision, she told Medscape Medical News in an interview.

A lumpectomy is considered to be successful when it shows a negative margin of tissue all around the cancer, Dr. Schnabel explained. However, this result is known only from the pathology report, which is sent back several days after the surgery has taken place.

At present, about 20% of women who undergo a lumpectomy in the United States have to return for further surgery because pathologist testing of the removed tissue shows that there was cancer in the margins, Dr. Schnabel said.

This new device allows the testing of the margins to take place intraoperatively, she said. In the trial, the device was used to test tissue in 5 areas on each of 6 surfaces of the removed breast tissue, she explained, and if any 1 of these tested positive for cancer, further tissue was removed.

The women in this trial had early breast cancer, both distal carcinoma in situ (DCIS) and invasive carcinoma, and they all had nonpalpable disease that had been discovered on mammography or other imaging, Dr. Schnabel noted. "This is a population that poses a bigger challenge for the surgeon to understand where the disease begins and ends; there are fewer cues that you can see and feel to help you determine the extent of tissue to be removed," she said.

Clinical Data Presented at Meetings

This trial is awaiting publication, but some of the data were presented recently at the 2012 Breast Cancer Symposium and were highlighted in a press briefing organized by the American Society of Clinical Oncology. At that time, Susan Boolbol, MD, a breast surgeon at Beth Israel Medical Center in New York City, reported that the device significantly decreased the re-excision rate without significantly increasing the total amount of tissue removed. In a cohort of patients with both DCIS and invasive cancer, the re-excision rates were 17% with the device compared with 33% in control patients (P < .001).

Clinical experience with the device was also discussed at the 2011 annual meeting of the American Society of Breast Surgeons. At that time, Lorraine Tafra, MD, from the Anne Arundel Breast Center, Annapolis, Maryland, presented early data from the 664-patient trial that were used in the approval application.

She reported a successful complete surgical resection rate of 72% with use of the device, compared with 22% in the control group (P < .0001). Significantly, fewer patients underwent re-excision in the device group than in the control group (33 vs 62 patients, P = .001), she said.

"The device has been engineered to give you only 1 of 2 answers — yes or no," Dr. Tafra told Medscape Medical News at the time. If a reading comes back positive, "you can make the decision to widen the margins there and then," she said.

"Margins are becoming more and more important because tumors are getting smaller and more and more patients are getting lumpectomies," Dr. Tafra told Medscape Medical News. "The challenge is to tailor your surgery and try to take out enough tissue so margins are clear, but not to take too much out, otherwise it will deform the breast. This device gives us a very quick and accurate assessment of the margins in the [operating room]."

Another investigator who had also participated in the trial, Sheldon Feldman, MD, from Columbia University in New York City, said: "We are very enthusiastic about this, as we want to remove the right amount of tissue, but not too much." The next step, he added, would be to develop a device that can test for the presence of residual disease within the lumpectomy cavity itself.

"We care more about what has not been removed than what has been removed, so the next step would be to develop a device that would allow us to doublecheck and see what's still in there," he added.