V. Del Chiaro1, M. G. Huey1, M. Adams2, S. R. Vemuru1, D. E. Wolverton3, A. Hartwick4, S. Sams4, A. A. Berning4, L. McLemore4, N. Christian1, S. Tevis1 1University Of Colorado Anschutz Medical Center, Department Of Surgery, Aurora, CO, USA 2University Of Colorado School of Medicine, Adult And Child Center For Outcomes Research And Delivery Science (ACCORDS), Aurora, CO, USA 3University Of Colorado Anschutz Medical Center, Department Of Radiology, Aurora, CO, USA 4University Of Colorado Anschutz Campus School of Medicine, Department Of Pathology, Aurora, CO, USA
Introduction: Compared to mastectomy, breast conserving surgery (BCS) has equivalent oncologic outcomes for breast cancer treatment and is associated with lower postoperative morbidity and higher patient satisfaction. Key to achieving these outcomes is obtaining negative resection margins during BCS. Previous studies have reported wide variability in margin positivity and re-excision rates after BCS. One center utilizes a multidisciplinary team consisting of surgeons, pathologists, and radiologists to assess breast specimens in real-time during BCS and has demonstrated superior rates of re-excision; this method has not been redemonstrated at other institutions. In this pilot study, we aimed to examine the feasibility of implementing this process at a comprehensive cancer center.
Methods: From March 2022 to present, patients with stage 0-III breast cancer undergoing lumpectomy with sentinel node biopsy were invited to participate in this pilot study evaluating the feasibility of the multidisciplinary intraoperative margin assessment protocol outlined in Figure 1. This was performed in lieu of cavity shave margins which were typically performed at our institution. Informed consent was obtained from all enrolled patients. Time points were collected for all steps in the process. The primary outcome was the rate of positive margins on final pathology defined using consensus guidelines. Secondary outcomes were weight and volume of additional margins excised after the multidisciplinary discussion. The balancing measure was the time elapsed during the margin assessment process beginning from the time the specimen was excised to the completion of the multidisciplinary discussion.
Results: Eight patients were enrolled in the study. This multidisciplinary process took an average of 50.5 minutes (range 38-74 minutes). Assessment of the whole and serially sectioned radiographs followed by multidisciplinary discussion took an average of 32 minutes (range 25-44 minutes) and led to a recommendation of additional margin resection in six patients (75%). Margin positivity occurred in one patient out of eight (12.5%), but no further tissue could be excised given that the positive anterior margin of the specimen was at the anterior mastectomy plane. Re-excision was not recommended, and the patient proceeded with radiation therapy. For the six patients with additional margins excised, the mean volume of excised tissue was 5.2 cm3 (SD 2.3 cm3) and mean weight was 2.3 g (SD 0.9 g).
Conclusion: The preliminary results from this pilot study suggest that a multidisciplinary intraoperative assessment of lumpectomy specimens may be an efficient and effective method to evaluate margins in patients undergoing BCS. Data from a larger patient cohort to validate these results are forthcoming.
