Abstract CT245: Feasibility study to evaluate performance of the Lum Imaging System for intraoperative detection of residual tumor in patients with breast cancer receiving neoadjuvant therapy

Abstract

Abstract Background: Microscopically tumor-free lumpectomy margins are critical for safe breast conserving surgery. With current tools, 15% to 25% of lumpectomies have positive margins and require a second surgical procedure increasing cost and patient discomfort. In addition, current lumpectomy margin assessment techniques show poor performance in predicting residual disease at re-excision, with a PPV of 35%. Better detection tools are needed to identify residual cancer during the initial lumpectomy and reduce second operations. LUM015 is a protease-activated fluorescent imaging agent that accumulates in tumor cells and tumor associated macrophages injected intravenously before surgery. The LUM Imaging System visualizes the activated LUM015 in the lumpectomy cavity via a hand-held wide field detector and proprietary tumor detection software. This system was previously tested in multiple single-site studies and a large, prospective 234 patient multi-site study that demonstrated successful detection of residual lumpectomy cavity. Initial studies excluded the approximately 20% of breast cancer patients receiving neoadjuvant therapy. Patchy tumor cell death with preoperative therapy can leave small, multifocal deposits of tumor in visible on pre-operative imaging and not palpable or visible during surgery. In this study, we evaluated the LUM Imaging System in this patient population. Trial Design: A prospective, multi-center study was designed to test feasibility of the LUM Imaging System in lumpectomy surgery after neoadjuvant therapy. This will evaluate potential impact of microenvironment changes after treatment and tumor cell death on tumor detection algorithms. Algorithms will be refined if needed. 10 patients will address this objective. A second cohort will further evaluate the feasibility, safety and efficacy of the LUM Imaging System in this patient population. 114 patients with invasive breast cancer and/or ductal carcinoma in situ will enroll at 5 US medical centers. Exclusions include patients allergic to polyethylene glycol or intravenous contrast agents. Use of blue node mapping dyes before imaging with the LUM015 is not allowed. After excision of the main lumpectomy specimen, patients are randomized 1:3 to device or control arms. In the device arm, the cavity is imaged and margins with LUM015 signal are excised. In the control arm, the surgeon records images within the cavity but no LUM015-directed margins are excised. Final comprehensive shave margins are removed in both arms to evaluate extent of residual disease after the use of the LUM Imaging System or after standard lumpectomy resection. Cohort 1 has completed enrollment. No patients have enrolled into cohort 2. This trial is registered as NCT04440982. This study is funded by the NIH through a R01 research grant issued to Massachusetts General Hospital. Citation Format: Jorge Ferrer, Bridget Kelly, Alexandra Webster, Brian Schlossberg, Kate Smith, Manna Chang, Barbara Smith. Feasibility study to evaluate performance of the Lum Imaging System for intraoperative detection of residual tumor in patients with breast cancer receiving neoadjuvant therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT245.