Clinical trial NCT06529302: The OPBC-07/microNAC Study
Official title: Association of Axillary Lymph Node Dissection With Oncological Outcomes in Patients With Residual Micrometastases After Neoadjuvant Chemotherapy: The OPBC-07/microNAC Study
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Breast Cancer
Keywords: Neoadjuvant chemotherapy
Axillary lymph node dissection
Residual micrometastases
Lead sponsor: University Hospital, Basel, Switzerland
Sponsor class: OTHER
Collaborators: name: Memorial Sloan Kettering Cancer Center
First posted: 2024-07-31
Enrollment: 2000
Sex: ALL
Minimum age (years): 18
Maximum age (years): 100
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The study assesses consecutive patients with residual micrometastases after neoadjuvant chemotherapy, treated with or without axillary dissection. The data originate from participating Oncoplastic Breast Consortium (OPBC) centers as well as from the US and Brazil, and have been collect within the clinical routine between 2013 and 2024.

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.

Eligibility criteria: 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)

Primary outcomes:
measure: 5-year rate of any axillary recurrence
timeFrame: 5 years
measure: 5-year rate of isolated axillary recurrence
timeFrame: 5 years
measure: Comparison of 5-year rate of axillary recurrence in patients treated with and without axillary dissection
timeFrame: 5 years
Secondary outcomes:
measure: Proportion of patients with additional micro- and macrometastases removed by axillary lymph node dissection
timeFrame: 5 years
measure: 5-year rates of locoregional and any invasive recurrence
timeFrame: 5 years
measure: Comparison of 5-year rate of locoregional and any invasive recurrence in patients treated with and without axillary lymph node dissection
timeFrame: 5 years
Other outcomes:
Locations:
city: Phoenix
country: United States
facility: Valleywise Health Medical Center
state: Arizona
city: Los Angeles
country: United States
facility: Cedars-Sinai Medical Center
state: California
city: San Francisco
country: United States
facility: University of California
state: California
city: Santa Monica
country: United States
facility: Providence Saint John's Cancer Institute
state: California
city: Coral Gables
country: United States
facility: University of Miami
state: Florida
city: Boston
country: United States
facility: Dana-Farber Cancer Institute
state: Massachusetts
city: Ann Arbor
country: United States
facility: University of Michigan
state: Michigan
city: Rochester
country: United States
facility: Mayo Clinic
state: Minnesota
city: New York
country: United States
facility: NYU Langone Health
state: New York
city: New York
country: United States
facility: Memorial Sloan Kettering Cancer Center
state: New York
city: New York
country: United States
facility: Montefiore Medical Center
state: New York
city: Rochester
country: United States
facility: University of Rochester
state: New York
city: Durham
country: United States
facility: Duke University
state: North Carolina
city: Philadelphia
country: United States
facility: University of Pennsylvania
state: Pennsylvania
city: Philadelphia
country: United States
facility: Fox Chase Cancer Center
state: Pennsylvania
city: Pittsburgh
country: United States
facility: University of Pittsburgh Medical Center
state: Pennsylvania
city: Houston
country: United States
facility: MD Anderson Cancer Center
state: Texas
city: Seattle
country: United States
facility: Swedish Cancer Institute
state: Washington
city: Seattle
country: United States
facility: University of Washington
state: Washington
city: Quilmes
country: Argentina
facility: Sanatorio Modelo Quilmes
city: Sydney
country: Australia
facility: Chris O'Brien Lifehouse (COBL)
city: Linz
country: Austria
facility: Ordensklinikum Linz GmbH
city: Wien
country: Austria
facility: Medical University of Vienna Chirurgie
city: Brasilia
country: Brazil
facility: Hospital de Base do Distrito Federal
city: Brasilia
country: Brazil
facility: Sirio Libanes Hospital Brasilia
city: Curitiba
country: Brazil
facility: Hospital Nossa Senhora das Graças
city: Fortaleza
country: Brazil
facility: Hospital Geral de Fortaleza
city: Fortaleza
country: Brazil
facility: Instituto do Cancer do Ceará
city: Goiânia
country: Brazil
facility: Instituto de Mastologia e Oncologia
city: Goiânia
country: Brazil
facility: Hospital de Câncer Araújo Jorge
city: Sao Paulo
country: Brazil
facility: Sirio Libanes Hospital
city: Sao Paulo
country: Brazil
facility: Instituto D'OR de Pesquisa e Ensino
city: Montréal
country: Canada
facility: Sir Mortimer B. Davis Jewish General Hospital
city: Providencia
country: Chile
facility: Arturo Lopez Perez Foundation
city: Vitacura
country: Chile
facility: Institute of Radiation Medicine
city: Rijeka
country: Croatia
facility: Clinical Hospital Center Rijeka
city: Mansoura
country: Egypt
facility: Mansoura oncology center
city: Augsburg
country: Germany
facility: University Hospital Augsburg
city: Düsseldorf
country: Germany
facility: University Hospital Düsseldorf
city: Essen
country: Germany
facility: KEM | Clinics Essen-Mitte
city: Heidelberg
country: Germany
facility: University Hospital Heidelberg
city: Lübeck
country: Germany
facility: University Hospital Lübeck
city: Heraklion
country: Greece
facility: University General Hospital of Heraklion
city: Marousi
country: Greece
facility: Athens Medical Center
city: Ramat Gan
country: Israel
facility: Sheba Medical Center
city: Milano
country: Italy
facility: Insituto Europeo di Oncologia
city: Napoli
country: Italy
facility: University Hospital Federico II
city: Padova
country: Italy
facility: IOV Padua
city: Pavia
country: Italy
facility: Clinici Scientifici Maugeri IRCCS
city: Roma
country: Italy
facility: Fondazione Policlinico Universitario Agostino Gemelli IRCCS
city: Seoul
country: Korea, Republic of
facility: ASAN Medical Center
city: Seoul
country: Korea, Republic of
facility: Gangnam Severance Hospital
city: Seoul
country: Korea, Republic of
facility: Samsung Medical Center
city: Seoul
country: Korea, Republic of
facility: Seoul National University Hospital
city: Riga
country: Latvia
facility: Pauls Stradiņš Clinical University Hospital
city: Vilnius
country: Lithuania
facility: National Cancer Institute
city: Amsterdam
country: Netherlands
facility: The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital
city: Oslo
country: Norway
facility: Oslo University Hospital
city: Karachi
country: Pakistan
facility: Dow University of Health Sciences
city: La Victoria
country: Peru
facility: Hospital Nacional Guillermo Almenara Irigoyen
city: Surquillo
country: Peru
facility: Instituto Nacional de Enfermedades Neoplasicas
city: Zielona Gora
country: Poland
facility: University Hospital Zielona Gora
city: Lisboa
country: Portugal
facility: Champalimaud Foundation
city: Saint Petersburg
country: Russian Federation
facility: N.N. Petrov National Medical Research Center of Oncology
city: Banská Bystrica
country: Slovakia
facility: AGEL Mammacentrum sv. Agáty
city: Ljubljana
country: Slovenia
facility: Institute of Oncology Ljubljana
city: Barcelona
country: Spain
facility: Hospital del Mar d'Investigacions Mèdiques
city: Madrid
country: Spain
facility: Clinica Universidad de Navarra
city: Madrid
country: Spain
facility: Hospital Universitario La Paz, ía Mamaria
city: Stockholm
country: Sweden
facility: Capio Saint Göran's Hospital
city: Baden
country: Switzerland
facility: Cantonal Hospital Baden
city: Basel
country: Switzerland
facility: University Hospital Basel
city: Bern
country: Switzerland
facility: Campus SLB Sonnenhof AG
city: Lugano
country: Switzerland
facility: EOC Centro di Senologia della Svizzera Italiana
city: Luzern
country: Switzerland
facility: Cantonal Hospital Luzern
city: St. Gallen
country: Switzerland
facility: Tumor und Brustzentrum Ostschweiz
city: Winterthur
country: Switzerland
facility: Cantonal Hospital Winterthur
city: Zürich
country: Switzerland
facility: Zürich Breast Center
city: Zürich
country: Switzerland
facility: University Hospital Zürich
city: Ankara
country: Turkey
facility: Gülhane Training and Research Hospital
city: Fatih
country: Turkey
facility: Istanbul University Faculty of Medicine
city: Istanbul
country: Turkey
facility: Marmara University
city: Zonguldak
country: Turkey
facility: Zonguldak Bülent Ecevit University
city: Cambridge
country: United Kingdom
facility: Cambridge University Hospitals
Study officials:
affiliation: University Hospital, Basel, Switzerland
name: Walter Paul Weber, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
References: