Breast CancerNCT07829848
Response-Adapted Omission of Nodal Boost In N3 Breast Cancer After Neoadjuvant Systemic Therapy
A study testing standard boost and boost omission in people with Breast Cancer, run by Fudan University at 1 site in China.
Trial summary
Background Clinical N3 (cN3) breast cancer represents a high-risk subgroup of locally advanced disease. After neoadjuvant systemic therapy (NST), patients who achieve a clinical complete response (cCR) in initially involved but undissected nodal stations currently receive a boost to these regions as part of standard… Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Breast Cancer
- What is being tested?
- standard boost and boost omission
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 534 participants
- Where
- 1 siteChina
- Study dates
- 12 Sep 2026to 12 Sep 2033
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Female/male, aged 18-75 years.
- ECOG performance status 0-1.
- Histologically confirmed unilateral invasive breast cancer.
- No DM (M0), as confirmed by standard staging.
- cN3 disease, defined according to AJCC 8th staging system, confirmed by imaging and/or pathology, including any of the following: cN3a: metastasis to ipsilateral ICV nodes, with or without level I/II ALN involvement.
- cN3b: metastasis to ipsilateral IMNs with concurrent level I/II ALN involvement.
Show all 14Show fewer
- cN3c: metastasis to ipsilateral SCV nodes, with or without ALN or IMN involvement.
- Imaging confirmation is mandatory for all cN3 designations and may be performed using ultrasound, contrast-enhanced CT, MRI, or [18F]FDG PET-CT [16-18]. Across all modalities, abnormal features include, but are not limited to: abnormal enlargement (short-axis ≥5mm), rounded morphology with loss of the normal oval shape, solid appearance with effacement of the fatty hilum and cortical thickening, with or without irregular margins or necrosis. Modality-specific criteria include: heterogeneous enhancement on CT or MRI, or increased FDG uptake (SUVmax > mediastinal blood pool) on PET-CT. Pathological verification by fine-needle aspiration (FNA) or core needle biopsy (CNB) is recommended for SCV and ICV nodes when clinically feasible. If pathological confirmation is not obtained, the cN3 status is based solely on imaging criteria specified above.
- Completion of NST. Standard-of-care regimens must include at least four cycles of chemotherapy; Anti-HER2 targeted therapy is mandatory for HER2-positive disease, and immunotherapy may be added for eligible triple-negative breast cancer (TNBC). Clinical trial regimens are permitted per protocol, with or without chemotherapy, including novel agents (e.g., antibody-drug conjugates [ADCs], immunotherapies, anti-angiogenics, PARP inhibitors, or other investigational drugs). Both pathways are accepted provided the full protocol-specified course is completed.
- Underwent breast-conserving surgery (BCS) or mastectomy with levels I-II axillary lymph node dissection (ALND); IMN, SCV, and ICV nodes were left undissected. All surgical margins must be negative.
- Post-neoadjuvant imaging confirms no macroscopic residual disease in the initially involved but undissected nodal stations. The preferred modality is [18F]FDG PET-CT; ultrasound, contrast-enhanced CT or MRI are acceptable alternatives if PET-CT is unavailable. Imaging may be performed before or after surgery, but must be completed prior to randomization. For all modalities, cCR is defined as the complete disappearance of all previously involved but undissected lymph nodes. In cases where visible nodes persist on imaging, cCR may still be considered if: on PET-CT, no pathologic uptake; on ultrasound, CT, or MRI, nodes have normalized in size and morphology, and no suspicious features are present. Suspicious or equivocal findings require biopsy confirmation of negativity before randomization. All imaging studies must be interpreted by experienced radiologists using standardized criteria.
- Radiotherapy must start within 12 weeks of last surgery or last adjuvant chemotherapy cycle.
- Adjuvant systemic therapy per guidelines or trial protocols; investigational regimens require active trial enrollment.
- Written informed consent obtained.
Who cannot join
- Stage IV (metastatic) breast cancer.
- Prior or synchronous contralateral breast cancer.
- Macroscopic residual disease in the initially involved but undissected nodal stations (ICV, IMN, or SCV) in cN3 patients, as evidenced by post-neoadjuvant imaging and/or biopsy.
- Incomplete NST or no definitive breast/ALN surgery.
- Prior radiotherapy to the breast, CW, or regional nodes.
- History of other malignancies, except for adequately treated basal cell carcinoma of the skin or cervical carcinoma in situ (disease-free >3 years).
Show all 10Show fewer
- Current pregnancy or lactation.
- Severe uncontrolled comorbidities (e.g., cardiac, hepatic, renal, or infectious) precluding radiotherapy, as judged by the investigator.
- Known intolerance or contraindication to radiotherapy or to the planned adjuvant systemic therapy (chemotherapy, endocrine therapy, anti HER2 therapy, or immunotherapy).
- Inability or unwillingness to comply with protocol requirements.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Fudan University Shanghai Cancer Center
Shanghai, Shanghai Municipality, 200032
Jinli Ma, M.D., Ph.D., 86-21-64175590, ma-jinli@outlook.com
About this study
Official title: Omitting the Boost to Initially Involved But Undissected Nodal Stations That Achieved Clinical Complete Response After Neoadjuvant Systemic Therapy in cN3 Breast Cancer: A Phase III Randomized Study
Background Clinical N3 (cN3) breast cancer represents a high-risk subgroup of locally advanced disease. After neoadjuvant systemic therapy (NST), patients who achieve a clinical complete response (cCR) in initially involved but undissected nodal stations currently receive a boost to these regions as part of standard postoperative radiotherapy. However, whether this boost is necessary in this setting remains unknown, and prospective evidence on the safety of boost omission is lacking.
Objective The REACT-N3 trial aims to evaluate whether omitting the boost to undissected nodal stations that achieve cCR after NST is non-inferior to standard boost in terms of 3-year invasive breast cancer recurrence-free interval (IBCRFI), while reducing toxicity to adjacent organs.
Read more
Methods This is an open-label, multicenter, randomized phase 3 trial. Eligible patients are women with cN3 breast cancer who have completed NST, undergone breast/axillary surgery with the internal mammary, supraclavicular, and infraclavicular nodes left undissected, and have no macroscopic residual disease in these stations on post-NST [¹⁸F]FDG PET-CT or other imaging. Participants will be randomized 1:1 to receive either a standard boost (10 Gy in 5 fractions) or no boost to the initially involved but cCR-converted undissected nodal stations. Randomization is stratified by postoperative axillary nodal status (ypN- vs. ypN+), location of the involved nodal station (SCV vs. non-SCV), and molecular subtype (TNBC vs. non-TNBC). The primary endpoint is 3-year IBCRFI. Secondary endpoints include locoregional recurrence-free survival, distant metastasis-free survival, disease-free survival, overall survival, toxicity, and patient-reported outcomes. With a non-inferiority margin of 8%, a one-sided α of 0.05, 80% power, and 10% drop-out rate, a total of 534 patients will be enrolled.
Discussion The REACT-N3 trial will provide high-level evidence on the safety of boost omission in cN3 breast cancer patients with cCR after NST. If non-inferiority is confirmed, this strategy could establish a new, toxicity-sparing standard for regional nodal irradiation in this high-risk population.
- Conditions
- Breast Cancer
- Being tested
- standard boost, boost omission
- Keywords
- Clinical N3 breast cancer, neoadjuvant systemic therapy, clinical complete response, regional nodal irradiation, boost omission
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
standard boostRadiation
a boost dose of 10 Gy in 5 fractions to initially involved but undissected nodal stations that achieved clincial complete response after neoadjuvant systemic therapy
boost omissionRadiation
no boost to the initially involved but undissected nodal stations that achieved clinical complete response after neoadjuvant systemic therapy
| Study group | Role | What they receive |
|---|---|---|
| standard boost | Active comparator | a standard boost of 10Gy was delivered to the initially involved but undissected nodal stations that achieved clinical complete response Receives: Radiation: standard boost |
| boost omission | Experimental | no boost was given to the initially involved but undissected nodal stations that achieved clinical complete response after neoadjuvant systemic therapy Receives: Radiation: boost omission |
What is being measured
The primary outcome is the main question the study is designed to answer.
3-year invasive breast cancer (IBC) recurrence-free interval (RFI)
Measured: 3-year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Sep 2026
- Study start12 Sep 2026
- Primary completion12 Sep 2030 (estimated)
- Study completion12 Sep 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by Fudan UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 534 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Fudan University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jinli Ma, Fudan University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07829848
- Sponsor's protocol ID
- FDRT-BC-N3
- Status last verified
- Sep 2026
- First submitted
- 15 Sep 2026
- Last updated
- 23 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Omitting the Boost to Initially Involved But Undissected Nodal Stations That Achieved Clinical Complete Response After Neoadjuvant Systemic Therapy in cN3 Breast Cancer: A Phase III Randomized Study
- ClinicalTrials.gov ID
- NCT07829848
- Acronym / sponsor ID
- FDRT-BC-N3
- Conditions
- Breast Cancer
- Keywords
- Clinical N3 breast cancer, neoadjuvant systemic therapy, clinical complete response, regional nodal irradiation, boost omission
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 534 participants (estimated)
- Lead sponsor
- Fudan UniversityUniversity, hospital or other
- Study start
- 12 Sep 2026 (actual)
- Primary completion
- 12 Sep 2030 (estimated)
- Study completion
- 12 Sep 2033 (estimated)
- First posted
- 21 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background Clinical N3 (cN3) breast cancer represents a high-risk subgroup of locally advanced disease. After neoadjuvant systemic therapy (NST), patients who achieve a clinical complete response (cCR) in initially involved but undissected nodal stations currently receive a boost to these regions as part of standard postoperative radiotherapy. However, whether this boost is necessary in this setting remains unknown, and prospective evidence on the safety of boost omission is lacking.
Objective The REACT-N3 trial aims to evaluate whether omitting the boost to undissected nodal stations that achieve cCR after NST is non-inferior to standard boost in terms of 3-year invasive breast cancer recurrence-free interval (IBCRFI), while reducing toxicity to adjacent organs.
Methods This is an open-label, multicenter, randomized phase 3 trial. Eligible patients are women with cN3 breast cancer who have completed NST, undergone breast/axillary surgery with the internal mammary, supraclavicular, and infraclavicular nodes left undissected, and have no macroscopic residual disease in these stations on post-NST [¹⁸F]FDG PET-CT or other imaging. Participants will be randomized 1:1 to receive either a standard boost (10 Gy in 5 fractions) or no boost to the initially involved but cCR-converted undissected nodal stations. Randomization is stratified by postoperative axillary nodal status (ypN- vs. ypN+), location of the involved nodal station (SCV vs. non-SCV), and molecular subtype (TNBC vs. non-TNBC). The primary endpoint is 3-year IBCRFI. Secondary endpoints include locoregional recurrence-free survival, distant metastasis-free survival, disease-free survival, overall survival, toxicity, and patient-reported outcomes. With a non-inferiority margin of 8%, a one-sided α of 0.05, 80% power, and 10% drop-out rate, a total of 534 patients will be enrolled.
Discussion The REACT-N3 trial will provide high-level evidence on the safety of boost omission in cN3 breast cancer patients with cCR after NST. If non-inferiority is confirmed, this strategy could establish a new, toxicity-sparing standard for regional nodal irradiation in this high-risk population.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| standard boost | Active comparator | Radiation: standard boosta standard boost of 10Gy was delivered to the initially involved but undissected nodal stations that achieved clinical complete response |
| boost omission | Experimental | Radiation: boost omissionno boost was given to the initially involved but undissected nodal stations that achieved clinical complete response after neoadjuvant systemic therapy |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (14 listed)
- Female/male, aged 18-75 years.
- ECOG performance status 0-1.
- Histologically confirmed unilateral invasive breast cancer.
- No DM (M0), as confirmed by standard staging.
- cN3 disease, defined according to AJCC 8th staging system, confirmed by imaging and/or pathology, including any of the following: cN3a: metastasis to ipsilateral ICV nodes, with or without level I/II ALN involvement.
Key exclusion criteria (10 listed)
- Stage IV (metastatic) breast cancer.
- Prior or synchronous contralateral breast cancer.
- Macroscopic residual disease in the initially involved but undissected nodal stations (ICV, IMN, or SCV) in cN3 patients, as evidenced by post-neoadjuvant imaging and/or biopsy.
- Incomplete NST or no definitive breast/ALN surgery.
- Prior radiotherapy to the breast, CW, or regional nodes.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| standard boosta boost dose of 10 Gy in 5 fractions to initially involved but undissected nodal stations that achieved clincial complete response after neoadjuvant systemic therapy | Radiation | standard boost |
| boost omissionno boost to the initially involved but undissected nodal stations that achieved clinical complete response after neoadjuvant systemic therapy | Radiation | boost omission |
Primary outcome
3-year invasive breast cancer (IBC) recurrence-free interval (RFI)
Time frame: 3-year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Breast Cancer
Active, not recruiting
Streamlined Geriatric and Oncological Evaluation Based On IC Technology
Breast Cancer, Comorbidities and Coexisting Conditions
RecruitingPhase 2
Gene Signatures to Guide HR+MBC Therapy in a Diverse Cohort
Invasive Mammary Carcinoma, Metastatic Breast Cancer
Not yet recruitingObservational study
Comparison of Reliability, Time Cost, and Participant Comfort of Lymphedema Assessments in Upper Extremity
Lymphedema, Upper Extremity Lymphedema
RecruitingPhase 3
A Study of Camrelizumab Plus Chemotherapy in Combination With or Without Famitinib as Neoadjuvant Therapy in Participants With Triple Negative Breast Cancer (BCTOP-T-N01)
TNBC - Triple-Negative Breast Cancer
RecruitingPhase 3
Testing Whether Hormone Therapy With Ribociclib is as Effective as Chemotherapy Followed by Hormone Therapy With Ribociclib for the Treatment of High Anatomic Stage Breast Cancer With Low Recurrence Risk, The RxFINE-Low Trial
Anatomic Stage II Breast Cancer AJCC v8, Anatomic Stage IIIA Breast Cancer AJCC v8
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing standard boost and boost omission in people with Breast Cancer, run by Fudan University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 23 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
3-year invasive breast cancer (IBC) recurrence-free interval (RFI) (time frame: 3-year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Sep 2026.