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

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

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

Study Overview

• Status: Not yet recruiting
• Conditions: Lymphatic Metastasis; Breast Neoplasm Female
• Intervention / Treatment: Procedure: Radiotherapy

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Anticipated): 1380
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

1. women aged > 20 years
2. cT1-3N1M0, primary invasive
3. initially confirmed ALN by fine needle aspiration cytology before neoadjuvant chemotherapy
4. completion of neoadjuvant chemotherapy
5. tumors negative for LN metastasis confirmed by imaging after neoadjuvant chemotherapy

Exclusion Criteria:

1. synchronous distant metastases
2. previous other malignancy
3. bilateral breast cancer
4. previous primary systemic therapy
5. pregnancy or breastfeeding
6. pre-operative radiological evidence of multiple involved or suspicious axillary nodes
7. patient with psychiatric, addictive, or any disorder, which compromises ability to give informed consent for participation in this study.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

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

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of life by questionnaire	Pain, Discomfort, Numbness, Rotation of arm, Lymphedema of arm	5 years

Collaborators and Investigators

• Sponsor: Kyungpook National University Chilgok Hospital
• Collaborators: Korean Breast Cancer Study Group

Study record dates

Study Major Dates

• Study Start (Anticipated): July 1, 2020
• Primary Completion (Anticipated): June 30, 2023
• Study Completion (Anticipated): June 30, 2025

Study Registration Dates

• First Submitted: October 1, 2019
• First Submitted That Met QC Criteria: October 2, 2019
• First Posted (Actual): October 4, 2019

Study Record Updates

• Last Update Posted (Actual): October 4, 2019
• Last Update Submitted That Met QC Criteria: October 2, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Keywords: Breast cancer; Radiotherapy; Sentinel Lymph Node; cN1, ycN0; Neoadjuvant cheotherapy
• Additional Relevant MeSH Terms: Pathologic Processes; Skin Diseases; Neoplasms; Neoplasms by Site; Breast Diseases; Neoplastic Processes; Neoplasm Metastasis; Breast Neoplasms; Lymphatic Metastasis
• Other Study ID Numbers: 2019-09-023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No