NCT07546695Recruiting
Role of Axillary Lymph Node Dissection for Residual MACROMETASTASES After NEOADJUVANT Chemotherapy in Patients With HER2+ and Triple Negative Breast Cancer: The OPBC-11/MACRONAC Study
Summary
In this multicenter retrospective cohort study the aim is to determine the safety of omission of axillary lymph node dissection in patients with TNBC and HER2+ tumors with residual macrometastases (in the SLN/TAD/TAS or MARI node) after NAC.
Inclusion criteria
• Women and men with a diagnosis of stage I-III TNBC or HER2+ breast cancer at diagnosis. HER2+ is defined as an Immunohistochemistry (IHC) score of 3+ or positive FISH. TNBC is defined as ER and Progesterone Receptor (PR) IHC expression of 0 and HER2 negativity defined as either IHC expression of 0-1+ or lack of gene amplification (FISH \< 2.0). Patients with ER low (1-10%) and/or PR low (1-10%) tumors are allowed. • Any histological subtype • For Clinical Nodal Stage (cN) 0 at presentation: any axillary staging technique including palpation with or without imaging is allowed. Dual tracer mapping is not required for SLN surgery. • For cN+ at presentation: Percutaneous biopsy proven confirmation is required at diagnosis. Staging techniques after NAC include: SLN surgery with dual mapping or Targeted Axillary Dissection (TAD: imaging-guided localization of sampled node in combination with SLN procedure with or without dual mapping) or Tailored Axillary Surgery (TAS: removal of the sentinel lymph nodes as well as selective removal of all palpable disease and documentation of the removal of the initially biopsy-proven and clipped lymph node metastasis by specimen radiography) or the MARI procedure (Marking Axillary Lymph Nodes with Iodine Seeds). • Received neoadjuvant chemotherapy • Residual macrometastases (metastasis greater than 2 mm in diameter) detected on SLN surgery or TAD ot TAS or MARI (on frozen section or final pathology) • Concomitant presence of Isolated Tumor Cells (ITCs) and micrometastases in other sentinel lymph nodes is allowed • Following SLN surgery/TAD/TAS/MARI patients underwent completion ALND, nodal radiation therapy (RT), both or no further axillary treatment • At least 1-year follow-up (had surgery at any time point until October 2024 at the latest) - Prior history of ductal carcinoma in situ (DCIS) is allowed
Exclusion criteria
• Did not undergo SLN surgery/TAD/TAS/MARI (e.g., went straight to ALND) • Presence of ITCs or micrometastases alone in the sentinel nodes (or TAD nodes or MARI node or TAS nodes) without macrometastases • HR+HER2- tumors (except ER low and or PR-low) • Stage IV disease at presentation • Inflammatory breast cancer at presentation • Neoadjuvant endocrine therapy • Macrometastases detected by Oncoplastic Breast Consortium (OSNA)
Contacts
The trial team's contact details are shown on request.
See the official trial record- Status
- Recruiting
- Phase
- —
- Study type
- Observational
- Countries
- Switzerland
- Sponsor
- University Hospital, Basel, Switzerland(Other)
- Protocol no.
- 2026-00317 bb26Weber2
- Conditions
- Breast Cancer
- Interventions
- Other
Treatments studied
- Data Collection from medical records of from an already existing database "ONCOLOGICAL BREAST SURGERY DATABASE OF THE UNIVERSITY HOSPITAL OF BASEL" which was initiated in 2016.
Locations · 1
- Basel, SwitzerlandDepartment Breast, Abdomen, Pelvis; Universitätsspital BaselRecruiting at this site
In total, worldwide, the only site listed in the registry is recruiting.
Site status per the ClinicalTrials.gov registry (last update posted: May 19, 2026).
This status may have changed and says nothing about your eligibility: before taking any step, check with your oncologist or the site.
See also
Other versions
These results are indicative and do not replace medical advice — discuss them with your doctor.