E65: Positive pegulicianine fluorescence in the lumpectomy cavity correlates with tumor distance to margins

ePoster Abstract Author(s)

Irene Wapnir, MD

Professor of Surgery
Stanford University Medical Center
Stanford, CA, United States

Author(s)

Irene Wapnir, MD

Professor of Surgery
Stanford University Medical Center
Stanford, CA, United States
E. Shelley Hwang, MD, MPH

Mary and Deryl Hart Distinguished Professor of Surgery
Duke University School of Medicine
Durham, North Carolina, United States
Kelly K. Hunt, MD (she/her/hers)

Professor & Chair
Department of Breast Surgical Oncology, MD Anderson Cancer Center, Houston, TX, USA
Houston, Texas, United States
DC

David Carr, MD

General Surgeon
Novant Health, United States
PB

Peter Blumencranz, MD

General Surgeon
BayCare Medical Group, United States
KS

Kate P. Smith, MPH

Senior Director of Clinical Affairs
Lumicell, Inc.
Hudson, Massachusetts, United States
MC

Manna Chang, PhD

Principal Data Scientist
Lumicell, Inc, United States

Submitter(s)

JF

Jorge Ferrer, PhD

Senior Vice President Clinical Research and Strategy
Lumicell, Inc., United States

Author(s)

JF

Jorge Ferrer, PhD

Senior Vice President Clinical Research and Strategy
Lumicell, Inc., United States
Barbara L. Smith, MD, PhD

Professor of Surgery
Massachusetts General Hospital
Boston, Massachusetts, United States

Introduction: A randomized, two-arm study of pegulicianine fluorescence guided surgery (pFGS) at 14 US sites was conducted using a hand-held fluorescence imager to identify residual cancer in the lumpectomy cavity after the standard of care (SoC) tumor excision. We reported that pFGS detects residual cancer in the lumpectomy cavity, including in orientations pathologically negative on the SoC specimen. In addition, 15% (9 of 62) of patients with positive SoC margins were converted to final negative margins by taking pFGS-guided shaves, avoiding a second surgery. Interestingly, 8 of these 9 patients had no tumor found in the pFGS-guided shaves. We hypothesize that pFGS signal decreases as the tumor margin increases. We analyzed study data to assess correlation of pFGS signal with tumor margin distance, and its potential clinical value.

Methods: The pivotal study enrolled 406 patients undergoing lumpectomy for stage 0-III breast cancers. Patients received IV injection of pegulicianine 2-6 hours before surgery. After the SoC lumpectomy was completed, additional pFGS-guided shaves were excised at sites of positive pFGS signal in the lumpectomy cavity walls using a handheld imager and patient-calibrated cancer detection software. The rate at which pFGS indicates areas suspected to contain cancer was calculated as the ratio of orientations with positive pFGS signal to the total number of orientations with (1) negative margins, (2) positive margins and (3) positive margins with ink on tumor on the lumpectomy specimen. Positive margins were defined as ink on tumor for invasive cancer and tumor less than 2 mm from the margin for ductal carcinoma in situ (DCIS) alone.

Results: Results are presented in Table 1. We found a statistically significant higher positive fluorescence rate in orientations with positive margins (p=0.044). The positive fluorescence rate was even higher (21.1%) when only considering cases with ink on tumor.

Conclusions: By design, pegulicianine is activated by enzymes within the tumor and in stromal cells at the invasive front. Thus, when tumor is closer to the edge of the lumpectomy specimen, the rate of positive pFGS signal in the cavity increases, being highest when there is tumor present at the inked margin. This feature of pFGS guides the surgeon to resect more tissue in these areas in order to achieve a negative margin. The conversion of positive margins after the SoC lumpectomy to final negative margins prevents a second surgery, even when there is no tumor in the pFGS-guided margins. These findings have strengthened our understanding of the utility of this technology.

Learning Objectives:

Define the mechanism of action of pegulicianine to highlight regions to be removed to achieve negative margins.
Plan on how to use pFGS to assist during their lumpectomy surgery.
Describe the impact of pFGS on lumpectomy surgeries.