Evaluating the Effect of MarginProbe Use on Re-excisions After Partial Mastectomy: A Single-Institution Analysis.

Background: Breast conservation therapy is a widely accepted approach in treating breast cancer, yet the average re-excision rates are approximately 25% despite surgical advancements. The Food and Drug Administration (FDA)-approved MarginProbe device uses radiofrequency spectroscopy for intraoperative margin assessment, potentially reducing re-excision rates. This study evaluated the effectiveness of MarginProbe in reducing re-excisions compared with standard of care (SOC).

Methods: A prospective cohort with MarginProbe usage during partial mastectomies from June 2019 to July 2023 (153 patients) was compared with a retrospective control group without the device from January 2015 to May 2019 (300 patients). Both groups underwent partial mastectomies performed by two breast surgeons. Positive margins were defined as tumor on ink for invasive cancers and within 2 mm for ductal carcinoma in situ.

Results: When control was used for patient demographics and tumor characteristics, the findings showed that MarginProbe significantly decreased the probability of re-excision by 58% (p < 0.001), although it led to a higher shave volume, with an average of 9.8 cc additional tissue removed compared with SOC (p < 0.001). Human epidermal growth factor 2 (HER2) positivity was significantly associated with increased odds of re-excision (p = 0.036). MarginProbe demonstrated a sensitivity of 70.1% and a specificity of 47.5%.

Conclusions: MarginProbe is an effective adjunct for intraoperative margin assessment to decrease re-excision rates. However, patient selection is paramount. Given its significant increase in shave volume, women with small breasts may be at higher risk for poor cosmesis. Surgeons should exercise clinical judgement when determining the suitability of MarginProbe use for patients undergoing breast conservation. Further research is necessary to refine MarginProbe's specificity and to optimize its clinical application.