Breast cancer is notoriously difficult to reliably demarcate on preoperative imaging. And even with real-time intraop frozen section evaluation, the rate of positive margins on final path evaluation is as high as 20-40% meaning 1-2 of every 5 women require repeat surgery with a resulting hit in the final cosmetic outcome. The novel pegulicianine fluorescence–guided system (pFGS) is an imaging probe activated in the presence of cathepsins, secreted by cancer cells as a way to favorably remodel their surroundings. In this prospective single-arm study, 234 women received pegulicianine as a 3-min intravenous push 2-6 hours prior to breast-conserving surgery. Following tumor excision, they first underwent standard shaved-margin assessment followed by pFGS probe assessment. Across all involved lumpectomy cavity margins (n=62), pFGS dramatically increased sensitivity from 38% → 69%. Conversely, pFGS falsely identified 19 of 1522 (1.2%) negative margins.
- Hwang, JAMA Surg 2022