"It is clear to us that for women to have successful breast-conserving surgery and to make their risk for recurrence in the breast as low as possible, the edges of the lumpectomy must be completely free of cancer," Dr. Freya Schnabel, from New York University's Langone Medical Center in New York City, told Reuters Health.

But this can be difficult to achieve. "In the literature the rate of patients who need a second procedure to take out more tissue is somewhere in the 20% to 30% range," Dr. Schnabel said.

The new device uses radiofrequency spectroscopy to examine all surfaces of the tissue removed during lumpectomy. When placed directly on the tissue, it signals whether or not there appears to be cancerous tissue at the margins of excised specimens and the surgeon can remove additional tissue right away.

In the international multicenter study, 596 patients who were undergoing lumpectomy were randomized to have their excised tumors tested with the device or not.

Of the 298 patients in the device arm, 55% (163 patients) had at least one positive margin on the lumpectomy specimen; the same was true for 49% (147 of 298 patients) in the control arm.

The surgeons' ability to identify and resect all positive margins was significantly improved with the MarginProbe. The device enabled identification and resection of all positive margins in 117 patients (72%), whereas in the control arm, just 33 patients (22%) had all positive margins identified and resected (p < 0.0001).

The number of patients with positive margins was reduced by 57% in the device arm, cutting the re-excision rate in this group by 50%. Specifically, in the device arm, 31 patients (10.4%) required re-excision, compared with 62 patients (20.8%) in the control group (p = 0.001).

The device is straightforward to use, Dr. Schnabel, who led the U.S. portion of the study, said.

"This device represents a further refinement of breast conserving surgery," she said. "Hopefully, it will let us do the surgery in a more efficient way and let us accomplish what we need to accomplish with one procedure.

The device is commercially available in Europe. A spokesperson for Dune Medical Devices told Reuters Health that the company has filed an application with the U.S. Food and Drug Administration for use in the U.S. and has been granted accelerated, expedited review.

Dr. Michael Alvarado, a surgical oncologist at University of California, San Francisco, told Reuters Health he was excited to hear about this new device.

"In the U.S. for example, on average it's about a 50% chance that the woman will have to go back for a second surgery because of the margins after lumpectomy. In our institution, it's around 28% to 30%, which is better, but people have been trying to find better ways to assess the margins for a long time," Dr. Alvarado said.

Standard pathology to assess the margins using frozen section is extremely difficult to do on breast tissue and also takes a long time, he added.

"You are sitting in the operating room for upwards of 45 minutes to an hour for a frozen section if you have to do all the margins, so having something like this probe where you do it in real-time and get results within a few minutes would be a huge advantage," he said.

Coming back for a second procedure is also very costly and can often result in unnecessary mastectomies, Dr. Alvarado noted.

"Unfortunately, when a woman has a positive margin and you tell her she needs to go back for another surgery, some will say 'The heck with it, I'll just have a mastectomy, I don't want to take a chance of having this happen again'. So anything that reduces the chance of this happening is a positive advance."

By Fran Lowry

Last Updated: 2011-12-08 18:48:25 -0400 (Reuters Health)

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