One in five breast cancer conserving surgeries leaves behind some of the tumor. That means patients must schedule a second surgery and then endure additional pain, infection risk, recovery time and cost. Cairnsurgical Inc.'s Breast Cancer Locator system may change that by providing 3D tools that enable surgeons to precisely tailor resection to the shape, size and location of each tumor.

Investigators treated the first patient in the pivotal trial of the new system this week at Massachusetts General Hospital. “We are committed to participating in clinical research with the potential to improve outcomes for our patients with breast cancer,” said Suzanne Coopey, a breast oncology specialist at MGH who performed the first surgery using the Breast Cancer Locator (BCL) system. “We are very interested in evaluating whether this new approach to guiding the surgeon to tumor margins can make breast cancer surgery more accurate and reduce the need for additional surgery for positive margins.”

Current technologies meet radiologists’ needs much better than surgeons’ requirements. The typical prone MRI produces a sharp image, but patients are flipped on their backs for surgery, totally changing the shape and location of both breast and tumor. Likewise the “smashed breast” positioning used in mammograms provides a clearer view of abnormalities essential for diagnosis, but massively distorts the breast. Both leave surgeons largely flying blind as they plan tumor excision.

In addition, less than 20% of all breast tumors have a spherical shape. That makes techniques that place implants or wires in one or two central points in a tumor of very limited value in determining its shape, size, boundaries and margins. “Tumors often have irregular shapes and edges, and even ‘tentacles’ that are difficult to see clearly in imaging,” said David Danielsen, CEO of Cairnsurgical. “If something isn’t clear in imaging, it’s not clear to find in surgery.”

Helping surgeons plan

The BCL system creates a 3D image surgeons can manipulate as they plan and perform breast conserving surgeries. Credit: Cairnsurgical Inc.

Cairnsurgical took a different approach, one designed specifically to meet the needs of surgeons. “3D printing is a new capability, and we have utilized it and the supine MRI to create the Breast Cancer Locator, and to provide a unique guide for each patient with a detailed view of the size, shape, edges and margins of her specific tumor in the position it will be in for surgery,” Danielsen told BioWorld.

The first step in the system involves obtaining an MRI image with the patient in the position she will be in during surgery, on her back. That allows the system to analyze the tumor and gather the critical information to develop two surgical tools.

The first is a 3D-printed Breast Cancer Locator made of a medical-grade polymer using industrial 3D technology. With its shape guided by the data from the MRI, the BCL fits precisely over the patient’s breast. Its prepositioned ports for multiple central and bracketing wires guide the surgeon to the tumor boundaries and margins.

The surgeon also receives an interactive 3D image of the tumor, called the Visualizer. “The Visualizer is a 3D interactive image of the patient’s breast and tumor viewed on a standard monitor that the surgeon can use to help guide them to the tumor before and/or during the surgery – the image can be moved in space in any direction to see dimensions and location of the tumor, including edges, shape, margins, distance to the skin and chest wall to make surgery as precise as possible,” Danielsen explained.

“We developed the Breast Cancer Locator with the vision to provide improved clinical outcomes in order to reduce the positive margin rate. We want surgeons to be able to remove the entire tumor the first time, every time,” said Richard Barth, Jr., chief of general surgery, Dartmouth-Hitchcock Medical Center, Professor of Surgery, Geisel School of Medicine at Dartmouth, and Cairnsurgical co-founder.

Two pilot studies demonstrated that the system works quite well. The first, a single center study with 19 patients found that all 19 had negative tumor margins. The second, a multicenter study with 14 patients also had no patients with positive margins. “Our pilot studies are demonstrating that, by providing surgeons with a detailed blueprint of the tumor in the supine position, which we have never had before, we can reduce positive margins and enable surgeons to do more precise excisions,” Barth added.

Launching the pivotal trial

The Breast Cancer Locator study is a prospective, 1:1 randomized, controlled pivotal trial that will enroll 448 women with non-palpable invasive breast cancer or ductal carcinoma in situ (DCIS) tumors treated at 15 centers in the U.S. Patients will be randomized to receive either standard wire localization or BCL to guide surgery. The primary endpoint is positive margin rate. Other endpoints include specimen volume, rate of additional shave biopsies, re-excision rate, cancer localization rate, operative time and cost of care.

“We hope this tool will allow us to tailor the surgical resection to the best representation of the patient's own tumor,” said the study’s Principal Investigator Jennifer Gass, chief of surgery, Women & Infants Hospital, and professor of surgery, obstetrics and gynecology, The Warren Alpert Medical School of Brown University. “We have assembled a diverse group of study sites to evaluate the BCL in multiple settings, and look forward to comparing the ability of the technology to affect positive tumor margin, excision volume, and re-excision when compared to standard wire localization.”

Danielsen said enrollment in the study is expected to be completed in early 2022.