Gene Expression Profiling to Help Define the Need for Neo-Adjuvant Chemotherapy in HR+, HER- Breast Cancer Patients (NACAGEP)

The goal of the experiment is surgical de-escalation. Patients with newly diagnosed cT1-3, cN1, cM0 and HR+, HER2- breast cancer and low clinical risk usually first receive breast cancer surgery, after which chemotherapy can be added based on the final anatomopathological results or additional Gene Expression Profiling (GEP) testing.

Chemotherapy helps reduce the cancer recurrence or metastasis risk. Adjuvant chemotherapy (AC) can be given for large tumours, aggressive tumours with high grade tumour cells, or if axillary lymph node invasion is discovered during surgery. If the investigators were able to identify patients requiring chemotherapy prior to surgery, they could treat them with Neo-Adjuvant Chemotherapy (NAC) instead. By using MammaPrint® GEP, the investigators would be able to stratify patients into either a low- or high-risk category. Since the high-risk group is known to benefit from chemotherapy to improve overall survival, they would be treated with NAC, which could also potentially lead to surgical de-escalation. Breast conserving procedures, such as a lumpectomy instead of a mastectomy, could allow more aesthetically pleasing results and increase patient quality of life. Using NAC for patients with axillary lymph node invasion could lead to nodal complete pathological response (cN1 -> ypN0), allowing patients that are willing to enter the TADANAC trial a lymph node sparing procedure instead of a full axillary lymph node dissection.

Study Overview

• Status: Completed
• Conditions: Breast Cancer
• Intervention / Treatment: Diagnostic test: GEP

• Study Type: Observational
• Enrollment (Actual): 22

Contacts and Locations

Study Locations

• Belgium
  • Brussels Capital
    • Jette, Brussels Capital, Belgium, 1090
      • Universitair Ziekenhuis Brussel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients of the Breast Clinic

Description

Inclusion Criteria:

• Tumour characteristics: HR+, HER-
• Histopathological tumour characteristics: cT1-3, cN1, cM0, all histological types included
• Age: 18-85 years

Exclusion Criteria:

• Tumour characteristics: cT4, cN2-3, cM1
• Age: <18 or >85 years old
• Received chemotherapy in the last 5 years
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
De-escalation of breast cancer surgery	Number of patients who receive NAC after a high-risk GEP that will undergo TAD instead of ALND and/or undergo BCS instead of mastectomy	8 months after inclusion

Collaborators and Investigators

• Sponsor: Universitair Ziekenhuis Brussel

Study record dates

Study Major Dates

• Study Start (Actual): November 14, 2022
• Primary Completion (Actual): August 20, 2024
• Study Completion (Actual): August 20, 2024

Study Registration Dates

• First Submitted: December 16, 2022
• First Submitted That Met QC Criteria: December 16, 2022
• First Posted (Actual): December 27, 2022

Study Record Updates

• Last Update Posted (Actual): June 10, 2026
• Last Update Submitted That Met QC Criteria: June 8, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Neoadjuvant chemotherapy; GEP
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms
• Other Study ID Numbers: NACAGEP

Drug and device information, study documents

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