Massimo Ferrucci, MD, PhD
Veneto Institute of Oncology
Veneto Institute of Oncology
Padova, Veneto, Italy
Breast-conserving surgery (BCS) represents the gold standard for early breast cancer. However, positive margins remain a major concern, reported in 10–40% of cases, leading to re-excisions, increased costs, and poorer aesthetic results.
Traditional wire localization (WL) remains the most widespread method for guiding the excision of non-palpable lesions, but it has notable and well known drawbacks.
Newer wire-free techniques, such as magnetic seed localization, offer greater scheduling flexibility, lower migration risk, and high accuracy, although they remain costly and may cause MRI artifacts.
Alternatively, intraoperative ultrasound (IOUS) allows reliable real-time visualization of the lesion and margins, improving oncologic control and cosmetic outcomes, while potentially reducing costs compared with magnetic systems.
Despite encouraging evidence, robust comparative data between these localization techniques are lacking. The present study aims to compare the effectiveness, safety, and patient-centered outcomes of different localization strategies for non-palpable breast cancers.
Methods:
This is a phase 3, multicenter, randomized, open-label superiority clinical trial enrolling 1,302 patients with non-palpable breast cancer eligible for BCS. Participants will be randomized (1:1:1) to one of three pre-surgical localization techniques: IOUS (Arm A), magnetic guidance (Arm B), or WL (control arm). Randomization will be stratified by lesion type and clinical center.
The primary objective is to compare the positive margin rate between the 2 experimental arm and WL. Key secondary objective is pairwise comparisons between the two experimental arms.
Additional secondary endpoints assess safety (Clavien-Dindo complications, re-excision rate), cosmetic outcomes, patient and surgeon satisfaction (BREAST-Q, Likert scales), cost-effectiveness (EQ-5D-5L), and learning curvemetrics.
A difference of ≥7% in positive margin rate between WL (estimated 15%) and either experimental technique is considered clinically significant. With 434 patients per arm, the study has 80% power and a two-sided α=0.0167 to demonstrate superiority of the IOUS and magnetic guidance versus WL, in terms of proportion of positive margins.
Charitable and institutional funding, already received, will support the trial. Ethics Committee approval has been obtained. The study is registered at ClinicalTrials.gov (NCT07185568) and is now ready for patient enrollment.