Omitting Biopsy of SEntinel Lymph Node With Radiation After Neoadjuvant Chemotherapy in Breast Cancer (OBSERB) Trial

Study Overview
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Brief Summary
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The OBSERB study is a multi-center, non-blinded, pragmatic, parallel, randomized controlled trial in which patients with cT1-3N1 and ycN0 breast cancer.

Detailed Description
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The OBSERB study aims to compare the oncologic outcomes of radiotherapy without sentinel lymph node biopsy versus sentinel lymph node biopsy for the management of breast cancer which showed the cN1 was conversed as ycN0 after neoadjuvant chemotherapy. To verify whether, the radiotherapy without SLN can be applied, when the cN1 was conversed as ycN0 after neoadjuvant chemotherapy. To verify whether, the additional treatment decision can be established based on only the biology of primary tumor without the pathologic information of axillary lymph nodes To verify whether, the patients' quality of life can be improved by a less invasive surgical procedure, when the cN1 was conversed as ycN0 after neoadjuvant chemotherapy.

Official Title
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A Randomized Trial of Sentinel Lymph Node Biopsy vs Radiotherapy Alone After Neoadjuvant Chemotherapy in Patients Undergoing Breast Conserving Surgery With cT1-3N1, ycN0 Breast Cancer

Conditions
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Breast Neoplasm Female, Lymphatic Metastasis

Intervention / Treatment
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* Procedure: Radiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: women aged > 20 years cT1-3N1M0, primary invasive initially confirmed ALN by fine needle aspiration cytology before neoadjuvant chemotherapy completion of neoadjuvant chemotherapy tumors negative for LN metastasis confirmed by imaging after neoadjuvant chemotherapy Exclusion Criteria: synchronous distant metastases previous other malignancy bilateral breast cancer previous primary systemic therapy pregnancy or breastfeeding pre-operative radiological evidence of multiple involved or suspicious axillary nodes patient with psychiatric, addictive, or any disorder, which compromises ability to give informed consent for participation in this study.

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Sentinel lymph node biopsy<br>Perform conventional sentinel lymph biopsy | Procedure: Radiotherapy<br>* Adjuvant radiotherapy on axillary region<br>|
| Experimental: Adjuvant radiation without Sentinel lymph node biopsy<br>Perform radiotherapy instead of sentinel lymph node biopsy | Procedure: Radiotherapy<br>* Adjuvant radiotherapy on axillary region<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Disease-free survival | Disease free survival including breast, axilla and other organs from medical record | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Local recurrence | Ipsilateral breast from medical record | 5 years | 
| Axillary recurrence | Ipsilateral axillary lymph nodes from medical record | 5 years | 
| distant recurrence | Other organs except ipsilateral breast and axillary lymph nodes from medical record | 5 years | 
| distant free survival | No disease on other organs except ipsilateral breast and axillary lymph nodes from medical record | 5 years | 
| Overall survival | Overall survival from medical record | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast cancer, cN1, ycN0, Neoadjuvant cheotherapy, Sentinel Lymph Node, Radiotherapy