The OPBC-07/microNAC Study

Active, not recruiting

• Conditions: Breast Cancer

• Registration Number: NCT06529302
• Lead Sponsor: University Hospital, Basel, Switzerland

Brief Summary

The aim of this multicenter retrospective cohort study is to determine the safety of omission of axillary lymph node dissection in patients with residual micrometastases after neoadjuvant chemotherapy.

Detailed Description

Chemotherapy before surgery, known as neoadjuvant chemotherapy (NAC), is often used to treat patients with advanced breast cancer or aggressive early-stage breast cancer. Research shows that about one in four early-stage breast cancer patients receives this treatment.

For patients undergoing NAC, standard of care includes checking the lymph nodes under the arm (axillary lymph nodes) using a procedure called Sentinel lymph node biopsy to determine if the cancer has spread. In cases where the cancer has spread to the lymph nodes but then shrinks or disappears after chemotherapy, special techniques like dual tracer mapping, targeted axillary dissection, or the Marking Axillary Lymph Nodes with Iodine Seeds procedure are used to ensure accurate biopsy results.

For patients whose cancer shrinks completely in the lymph nodes, it is generally safe to skip further surgery to remove more lymph nodes, a procedure called axillary lymph node dissection (ALND). However, if cancer remains in the lymph nodes, more lymph nodes are typically removed because there is a high chance that cancer is still present.

An increasing number of surgeons are starting to omit ALND, especially when only tiny amounts of cancer (micrometastases) remain. To ensure this practice is safe, real-world data on patient outcomes over time is needed.

This multicenter retrospective cohort study aims to assess the safety of omitting ALND in patients with residual micrometastases after NAC for breast cancer. The study analyzes data of breast cancer patients treated between 2013 and 2024 at more than 50 centers that are part of the Oncoplastic Breast Consortium.

The results of this study will provide valuable information to help doctors determine the best treatment approach for their patients.

Study Timeline

• Study Start: 2024-05-15
• Study First Submitted: 2024-07-25
• Study First Submitted QC: 2024-07-30
• Study First Posted: 2024-07-31
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-23
• Last Update Posted: 2025-01-24
• Primary Completion: 2025-06
• Study Completion: 2025-06

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 2000

Inclusion Criteria

• Consecutive women and men aged 18 years or older with a diagnosis of stage I-III breast cancer (any histological and receptor subtype)
• For Clinically Node negative (cN0) at presentation: any axillary staging technique including palpation is allowed. Dual tracer mapping is not required for Sentinel Lymph Node Biopsy (SLNB)
• For Clinically Node positive (cN+) at presentation: Biopsy proven confirmation is required. Staging techniques include: SLNB with dual mapping or targeted axillary dissection (Targeted Axillary Dissection, TAD: imaging-guided localization of sampled node in combination with Sentinel Lymph Node procedure with or without dual mapping) or the Marking Axillary Lymph Nodes with Iodine Seeds (MARI) procedure
• Completed neoadjuvant chemotherapy
• Residual micrometastases detected on SLNB or TAD or MARI (on frozen section or final pathology)
• Concomitant presence of Isolated Tumor Cells (ITCs) and micrometastases in other sentinel lymph nodes is allowed
• Received axillary treatment with completion axillary lymph node dissection (ALND), axillary Radiotherapy (ART), both or none
• At least 1-year follow-up (inclusion should end in May 2023)
• Had surgery at any time point until May 2023 at the latest
• Prior history of stage I-III (not stage IV) breast cancer is allowed

Exclusion Criteria

• Did not undergo SLNB/TAD/MARI (e.g., went straight to ALND or ART)
• Presence of ITCs alone or macrometastases on the sentinel nodes (or TAD nodes or MARI node)
• Stage IV disease at presentation
• Inflammatory breast cancer at presentation
• Neoadjuvant endocrine therapy
• Micrometastases detected by One-step nucleic acid amplification (OSNA)

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Comparison of 5-year rate of axillary recurrence in patients treated with and without axillary dissection	5 years	The incidence of axillary recurrence is compared between patients that were treated with and without axillary dissection.
5-year rate of isolated axillary recurrence	5 years	Assessment of the incidence of isolated axillary recurrence.
5-year rate of any axillary recurrence	5 years	Assessment of the incidence of any axillary recurrence, which is defined as isolated or combined with local or distant recurrence.

Secondary Outcome Measures

Name	Time	Method
Comparison of 5-year rate of locoregional and any invasive recurrence in patients treated with and without axillary lymph node dissection	5 years	The incidence of locoregional and any invasive recurrence is compared between patients that were treated with and without axillary lymph node dissection.
Proportion of patients with additional micro- and macrometastases removed by axillary lymph node dissection	5 years	Assessment of the proportion of patients with additional micro- and macrometastases that were removed by axillary lymph node dissection.
5-year rates of locoregional and any invasive recurrence	5 years	Assessment of the incidence of locoregional and any invasive recurrence.

Trial Locations

Locations (84)

Valleywise Health Medical Center; 🇺🇸 Phoenix, Arizona, United States

Cedars-Sinai Medical Center; 🇺🇸 Los Angeles, California, United States

University of California; 🇺🇸 San Francisco, California, United States

Providence Saint John's Cancer Institute; 🇺🇸 Santa Monica, California, United States

University of Miami; 🇺🇸 Coral Gables, Florida, United States

Swedish Cancer Institute; 🇺🇸 Seattle, Washington, United States

Sanatorio Modelo Quilmes; 🇦🇷 Quilmes, Argentina

Chris O'Brien Lifehouse (COBL); 🇦🇺 Sydney, Australia

Ordensklinikum Linz GmbH; 🇦🇹 Linz, Austria

Medical University of Vienna Chirurgie; 🇦🇹 Wien, Austria

Sirio Libanes Hospital Brasilia; 🇧🇷 Brasilia, Brazil

Institute of Radiation Medicine; 🇨🇱 Vitacura, Chile

Clinical Hospital Center Rijeka; 🇭🇷 Rijeka, Croatia

Mansoura oncology center; 🇪🇬 Mansoura, Egypt

University Hospital Augsburg; 🇩🇪 Augsburg, Germany

University Hospital Düsseldorf; 🇩🇪 Düsseldorf, Germany

Hospital Nossa Senhora das Graças; 🇧🇷 Curitiba, Brazil

KEM | Clinics Essen-Mitte; 🇩🇪 Essen, Germany

University Hospital Federico II; 🇮🇹 Napoli, Italy

IOV Padua; 🇮🇹 Padova, Italy

Clinici Scientifici Maugeri IRCCS; 🇮🇹 Pavia, Italy

Sheba Medical Center; 🇮🇱 Ramat Gan, Israel

Insituto Europeo di Oncologia; 🇮🇹 Milano, Italy

Samsung Medical Center; 🇰🇷 Seoul, Korea, Republic of

Oslo University Hospital; 🇳🇴 Oslo, Norway

Champalimaud Foundation; 🇵🇹 Lisboa, Portugal

Hospital Universitario La Paz, ía Mamaria; 🇪🇸 Madrid, Spain

Capio Saint Göran's Hospital; 🇸🇪 Stockholm, Sweden

Cantonal Hospital Baden; 🇨🇭 Baden, Switzerland

University Hospital Basel; 🇨🇭 Basel, Switzerland

Campus SLB Sonnenhof AG; 🇨🇭 Bern, Switzerland

EOC Centro di Senologia della Svizzera Italiana; 🇨🇭 Lugano, Switzerland

Cantonal Hospital Luzern; 🇨🇭 Luzern, Switzerland

Tumor und Brustzentrum Ostschweiz; 🇨🇭 St. Gallen, Switzerland

Cantonal Hospital Winterthur; 🇨🇭 Winterthur, Switzerland

Zürich Breast Center; 🇨🇭 Zürich, Switzerland

University Hospital Zürich; 🇨🇭 Zürich, Switzerland

Gülhane Training and Research Hospital; 🇹🇷 Ankara, Turkey

Istanbul University Faculty of Medicine; 🇹🇷 Fatih, Turkey

Marmara University; 🇹🇷 Istanbul, Turkey

Zonguldak Bülent Ecevit University; 🇹🇷 Zonguldak, Turkey

Cambridge University Hospitals; 🇬🇧 Cambridge, United Kingdom

Dana-Farber Cancer Institute; 🇺🇸 Boston, Massachusetts, United States

University of Michigan; 🇺🇸 Ann Arbor, Michigan, United States

Mayo Clinic; 🇺🇸 Rochester, Minnesota, United States

NYU Langone Health; 🇺🇸 New York, New York, United States

Memorial Sloan Kettering Cancer Center; 🇺🇸 New York, New York, United States

Montefiore Medical Center; 🇺🇸 New York, New York, United States

University of Rochester; 🇺🇸 Rochester, New York, United States

Duke University; 🇺🇸 Durham, North Carolina, United States

University of Pennsylvania; 🇺🇸 Philadelphia, Pennsylvania, United States

Fox Chase Cancer Center; 🇺🇸 Philadelphia, Pennsylvania, United States

University of Pittsburgh Medical Center; 🇺🇸 Pittsburgh, Pennsylvania, United States

MD Anderson Cancer Center; 🇺🇸 Houston, Texas, United States

University of Washington; 🇺🇸 Seattle, Washington, United States

Hospital de Base do Distrito Federal; 🇧🇷 Brasilia, Brazil

Instituto do Cancer do Ceará; 🇧🇷 Fortaleza, Brazil

Instituto de Mastologia e Oncologia; 🇧🇷 Goiânia, Brazil

Hospital Geral de Fortaleza; 🇧🇷 Fortaleza, Brazil

Hospital de Câncer Araújo Jorge; 🇧🇷 Goiânia, Brazil

Sirio Libanes Hospital; 🇧🇷 Sao Paulo, Brazil

Instituto D'OR de Pesquisa e Ensino; 🇧🇷 Sao Paulo, Brazil

Sir Mortimer B. Davis Jewish General Hospital; 🇨🇦 Montréal, Canada

Arturo Lopez Perez Foundation; 🇨🇱 Providencia, Chile

University Hospital Heidelberg; 🇩🇪 Heidelberg, Germany

University Hospital Lübeck; 🇩🇪 Lübeck, Germany

University General Hospital of Heraklion; 🇬🇷 Heraklion, Greece

Athens Medical Center; 🇬🇷 Marousi, Greece

Fondazione Policlinico Universitario Agostino Gemelli IRCCS; 🇮🇹 Roma, Italy

ASAN Medical Center; 🇰🇷 Seoul, Korea, Republic of

Gangnam Severance Hospital; 🇰🇷 Seoul, Korea, Republic of

Seoul National University Hospital; 🇰🇷 Seoul, Korea, Republic of

Pauls Stradiņš Clinical University Hospital; 🇱🇻 Riga, Latvia

National Cancer Institute; 🇱🇹 Vilnius, Lithuania

The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital; 🇳🇱 Amsterdam, Netherlands

Instituto Nacional de Enfermedades Neoplasicas; 🇵🇪 Surquillo, Peru

University Hospital Zielona Gora; 🇵🇱 Zielona Gora, Poland

Dow University of Health Sciences; 🇵🇰 Karachi, Pakistan

Hospital Nacional Guillermo Almenara Irigoyen; 🇵🇪 La Victoria, Peru

N.N. Petrov National Medical Research Center of Oncology; 🇷🇺 Saint Petersburg, Russian Federation

AGEL Mammacentrum sv. Agáty; 🇸🇰 Banská Bystrica, Slovakia

Institute of Oncology Ljubljana; 🇸🇮 Ljubljana, Slovenia

Hospital del Mar d'Investigacions Mèdiques; 🇪🇸 Barcelona, Spain

Clinica Universidad de Navarra; 🇪🇸 Madrid, Spain