A novel surgical guidance system could transform the standard approach to breast cancer treatment by potentially reducing or eliminating the need for radiation therapy in certain patients. These findings emerged from a two-arm, blinded study presented at the 2024 San Antonio Breast Cancer Symposium (SABCS).
The study evaluated LumiSystem, which combines the Lumicell Direct Visualization System with pegulicianine (Lumisight), as an adjunct to standard lumpectomy surgery. Among 357 patients who received LumiSystem-guided surgery, 166 (46.5%) underwent additional excisions guided by the technology following their standard lumpectomy procedure.
Improved Surgical Outcomes
The results showed remarkable success in achieving negative margins, with 133 out of 166 patients (80.1%) achieving this crucial surgical goal. Of particular significance, 77 patients (46.4%) became eligible to omit radiotherapy after their standard lumpectomy, representing a substantial opportunity for treatment de-escalation.
In the subset of patients eligible for radiation omission, nine individuals (11.7%) had subsequent LumiSystem-guided excisions that revealed residual tumor deposits ranging from 1 to 11 millimeters, including cases with grade 3 histology. The median age of these patients was 51 years, spanning from 51 to 77 years.
Impact on Radiation Planning
The technology demonstrated particular value in cases with positive margins. Among 33 patients who initially had positive margins after standard lumpectomy, nine (27.3%) were converted to negative margins intraoperatively using LumiSystem guidance. Moreover, three patients became eligible for complete radiation omission, while two qualified for reduced radiation treatment volumes.
"These findings could address the five-fold risk of recurrence with versus without radiotherapy in this setting," noted Dr. Simona F. Shaitelman, lead study author and professor in the Department of Radiation Oncology at The University of Texas MD Anderson Cancer Center. She emphasized that historical recurrences without radiotherapy might have been due to residual disease that went undetected during surgery.
Safety and Implementation
The safety profile of the system appears manageable, with 406 patients receiving pegulicianine (1.0 mg/kg) via intravenous infusion 2 to 6 hours before surgery. While blue chromaturia was common (observed in 367 patients), only two patients experienced serious grade 3 adverse events related to pegulicianine, specifically hypersensitivity and anaphylactic reaction, leading to discontinuation.
The study's radiation therapy decisions were based on established criteria from multiple prospective clinical trials, considering factors such as age, margin size, tumor characteristics, hormone receptor status, node status, and cancer stage. Two independent radiation oncologists made these assessments retrospectively.
This innovative approach to breast cancer surgery could significantly impact patient care by minimizing tissue toxicity, reducing healthcare costs, and improving cosmetic outcomes through more precise surgical margins and potentially reduced need for radiation therapy.
