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Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

No Axillary Surgical Treatment in Clinically Lymph Node Negative Patients on Ultrasonography After Neoadjuvant Chemotherapy

No Axillary Surgical Treatment in Clinically Lymph Node Negative Patients on Ultrasonography After Neoadjuvant Chemotherapy: A Prospective, Phase III Clinical Trial

No Axillary Surgical Treatment in Clinically Lymph Node Negative Patients on Ultrasonography After Neoadjuvant Chemotherapy (NCT06704945) is a Phase 3 interventional studying Breast Cancer and Neoadjuvant Therapy, sponsored by Seoul National University Hospital. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

Important: This information is not medical advice. Talk to your doctor about whether a clinical trial is right for you.

About This Trial

NEO-NAUTILUS is a prospective, multicenter, randomized phase III clinical trial to evaluate whether omitting axillary lymph node surgery (ALND or SLNB) in clinically lymph node-negative breast cancer patients after neoadjuvant chemotherapy is non-inferior to performing SLNB in terms of 5-year disease-free survival.

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For Breast Cancer, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 464 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: - Women aged ≥19 years. - diagnosed by tissue sample (biopsy-confirmed) invasive breast carcinoma treated with neoadjuvant chemotherapy. - Clinical staging prior to NAC: cT1-3, cN0, M0 (AJCC 8th Edition). - If pre-NAC staging is cT1-3, cN1, M0, must meet the following criteria: 1. HER2-positive or triple-negative breast cancer (TNBC). 2. At least 30% reduction in tumor size on MRI after NAC (comparing pre- and post-NAC MRI). - Negative axillary lymph node status on ultrasound after NAC. - Planned for breast-conserving surgery with completed neoadjuvant chemotherapy (at least half the planned regimen must be completed). - You should be able to carry out daily activities with 0 level of ability (ECOG 0)-2. - Signed written willing to sign a consent form before enrollment. Who Should NOT Join This Trial: - History of any cancer within the past 5 years. - Bilateral breast cancer. - Patients requiring mastectomy. - Tumor size \>5 cm after NAC. - Male breast cancer. - Pregnant or breastfeeding women. - Inability to understand and complete questionnaires. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language
Inclusion Criteria: * Women aged ≥19 years. * Histologically confirmed invasive breast carcinoma treated with neoadjuvant chemotherapy. * Clinical staging prior to NAC: cT1-3, cN0, M0 (AJCC 8th Edition). * If pre-NAC staging is cT1-3, cN1, M0, must meet the following criteria: 1. HER2-positive or triple-negative breast cancer (TNBC). 2. At least 30% reduction in tumor size on MRI after NAC (comparing pre- and post-NAC MRI). * Negative axillary lymph node status on ultrasound after NAC. * Planned for breast-conserving surgery with completed neoadjuvant chemotherapy (at least half the planned regimen must be completed). * ECOG performance status of 0-2. * Signed written informed consent before enrollment. Exclusion Criteria: * History of any cancer within the past 5 years. * Bilateral breast cancer. * Patients requiring mastectomy. * Tumor size \>5 cm after NAC. * Male breast cancer. * Pregnant or breastfeeding women. * Inability to understand and complete questionnaires.

Treatments Being Tested

PROCEDURE

No axillary surgery

BCS only. Ommission of axillary surgery. No axillary surgery after neoadjuvant chemotherapy.

PROCEDURE

Axillary surgery

BCS with SLNB(+/-ALND)

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Seoul National University Hopsital
Seoul, South Korea

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06704945), the sponsor (Seoul National University Hospital), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06704945 clinical trial studying?

NEO-NAUTILUS is a prospective, multicenter, randomized phase III clinical trial to evaluate whether omitting axillary lymph node surgery (ALND or SLNB) in clinically lymph node-negative breast cancer patients after neoadjuvant chemotherapy is non-inferior to performing SLNB in terms of 5-year disease-free survival. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06704945?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06704945?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06704945. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06704945. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.