Device Assists Surgeons in Obtaining Negative Margins During Breast-Conserving Surgery: Presented at SABCS
By Alex Morrisson
SAN ANTONIO -- December 13, 2011 -- A device that signals surgeons to the presence of cancers cells at the margin of resected tissue appears to reduce the necessity to perform second surgeries on women undergoing breast-conserving therapy, according to a study presented here at the 34th Annual San Antonio Breast Cancer Symposium (SABCS).
“Second surgeries are difficult on the patient, both physically and emotionally,” said Freya Schnabel, MD, New York University Langone Medical Center, New York, New York, in presenting her poster on December 8.
“On average, about 30% of patients will require more than 1 surgery to completely remove the cancer,” she said. “In our study, we saw a similar rate in the control arm, but by using MarginProbe, we were able to cut that in half. This represents a substantial improvement in patient care and quality, as well as reducing costs.”
In the 596-patient randomised study, adjunctive use of MarginProbe significantly improved surgical outcomes by improving surgeons’ ability to identify and immediately resect positive margins, reducing the number of patients requiring re-excision by 57%.
The device is able to access cancer cells at tissue margins as surgeons operate. The probe does not touch the patients, but is used along the edges of the resected tissue. Transmitted radiofrequency signals distinguished between known properties of cancer and noncancerous tissue. The device emits a signal if cancerous cells are detected within 1 mm of the margin. If such a signal is detected, then a further excision can be made at the time of surgery.
In the prospective, international study, researchers in 21 centres used the device or performed standard surgery. The randomisation occurred in the operating room. Pathologists were not told whether the device was used as they determined if additional treatment was needed and the basis of positive margins.
Of the 298 patients in each arm, 55% of the main lumpectomy specimens in the device arm had at least one positive margin, compared with 49% of the main lumpectomy specimens in the control group.
Those surgeons who were assigned use of the MarginProbe were significantly more likely to identify and resect all positive margins than controls. Dr. Schnabel reported that 72% of the 163 cases in which positive margins were observed in the main lumpectomy were resected successfully among the surgeons using the probe. Just 22% of the surgeons in the control arm were able to successfully resect to negative margins (P <.0001).
“Following lumpectomy, the number of patients having positive margins due to failed intraoperative assessment was reduced by 57% in the device arm, leading to a 50% reduction in re-excisions for this group,” Dr. Schnabel said.
She noted that use of the device did not significantly increase the volume of tissue removed.
“Adjunctive use of MarginProbe during breast-conserving surgery significantly improved surgical outcomes by improving surgeons’ ability to identify and immediately resect positive margins,” she said.
The device is commercially available in Europe. It is being investigated for approval in the United States.
Funding for this study was provided by Dune Medical Devices.
[Presentation title: A Randomized, Prospective, Multicenter Study of the Impact of Intraoperative Margin Assessment With Adjunctive Use of MarginProbe vs. Standard of Care. Abstract PD02-04]
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