Predictive Factors for CNS Metastases in Early Breast Cancer Using Liquid Biopsy (AKRA CŽS) (AKRA CŽS)

February 26, 2026 updated by: Institute of Oncology Ljubljana

Predictive Factors in Primary Tumor and Liquid Biopsy for the Spread of Early Breast Cancer to the Central Nervous System

Breast cancer is the most common cancer in women. Although most patients are diagnosed at an early stage and treated with curative intent, some later develop metastases to the central nervous system (CNS), which are associated with poor prognosis and high morbidity. Currently, there are no validated biomarkers that reliably predict which patients with early-stage breast cancer are at increased risk for CNS metastases.

This study aims to identify molecular predictors of CNS metastases in early breast cancer. Gene expression profiles (mRNA) from archived primary tumor tissue will be analyzed using next-generation sequencing (NGS). In addition, serum concentrations of chemokines CX3CL1, CXCL13, and CXCL8 (IL-8), measured at the time of diagnosis using ELISA, will be evaluated for their association with subsequent CNS metastases.

The results may improve risk stratification and support earlier identification of patients at increased risk for CNS spread.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Breast cancer is frequently diagnosed at an early stage. Despite appropriate curative treatment, a subset of patients develops distant metastases during follow-up. Metastases to the central nervous system (CNS) represent a serious clinical complication due to their significant impact on morbidity and mortality. At present, no validated blood-based biomarkers are available to reliably predict CNS dissemination in patients with early-stage breast cancer.

The primary objective of this study is to identify genes that are differentially expressed in archived primary breast tumor tissue of patients who subsequently developed CNS metastases compared with matched controls who did not develop CNS metastases. Gene expression will be assessed using next-generation sequencing (NGS) of cDNA derived from mRNA.

The secondary objective is to evaluate whether baseline serum concentrations of chemokines CX3CL1, CXCL13, and CXCL8 (IL-8), measured using enzyme-linked immunosorbent assay (ELISA), are associated with the later development of CNS metastases.

The study includes two clinically comparable groups of patients with early-stage breast cancer:

patients who developed CNS metastases during follow-up, and

matched control patients without CNS metastases.

Statistical analyses will include descriptive statistics, univariate and multivariate logistic regression models, and receiver operating characteristic (ROC) curve analysis to evaluate predictive performance of the investigated biomarkers.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
22

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Slovenia
      • Ljubljana, Slovenia, 1000
        • Institute of Oncology Ljubljana

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Female patients aged 18 years or older.
  • Diagnosis of early-stage breast cancer.
  • Availability of archived primary tumor tissue suitable for mRNA analysis.
  • Availability of serum sample suitable for chemokine analysis.
  • Patients included in the AKRA cohort with documented follow-up data.
  • Patients with confirmed CNS metastases during follow-up (CNS metastases group) or matched controls without CNS metastases (control group).

Exclusion Criteria:

  • Male breast cancer patients.
  • Lack of sufficient primary tumor tissue for mRNA analysis.
  • Lack of available serum sample for chemokine analysis.
  • Incomplete clinical follow-up data preventing classification of CNS metastasis status.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: CNS Metastases Group
Female patients with early-stage breast cancer who developed central nervous system (CNS) metastases during follow-up. Participants undergo molecular biomarker assessment consisting of primary tumor mRNA gene expression profiling using next-generation sequencing (NGS) and measurement of baseline serum chemokine concentrations (CX3CL1, CXCL13, CXCL8 [IL-8]) using ELISA.
Diagnostic test: Primary Tumor mRNA Expression Profiling (NGS)
Gene expression profiling of mRNA derived from archived primary breast tumor tissue using next-generation sequencing (NGS) to identify genes differentially expressed between patients who developed CNS metastases and matched controls.
Diagnostic test: Serum Chemokine Quantification (ELISA)
Measurement of serum concentrations of chemokines CX3CL1, CXCL13, and CXCL8 (IL-8) collected at diagnosis using enzyme-linked immunosorbent assay (ELISA) to evaluate their association with subsequent CNS metastases.
Active Comparator: Control Group (No CNS Metastases)
Matched female patients with early-stage breast cancer who did not develop CNS metastases during follow-up. Participants undergo molecular biomarker assessment consisting of primary tumor mRNA gene expression profiling using next-generation sequencing (NGS) and measurement of baseline serum chemokine concentrations (CX3CL1, CXCL13, CXCL8 [IL-8]) using ELISA.
Diagnostic test: Primary Tumor mRNA Expression Profiling (NGS)
Gene expression profiling of mRNA derived from archived primary breast tumor tissue using next-generation sequencing (NGS) to identify genes differentially expressed between patients who developed CNS metastases and matched controls.
Diagnostic test: Serum Chemokine Quantification (ELISA)
Measurement of serum concentrations of chemokines CX3CL1, CXCL13, and CXCL8 (IL-8) collected at diagnosis using enzyme-linked immunosorbent assay (ELISA) to evaluate their association with subsequent CNS metastases.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Differential Gene Expression in Primary Tumor Tissue Associated With CNS Metastases
Time Frame: Up to 36 months after baseline
Identification of genes differentially expressed in primary breast tumor tissue between patients who developed CNS metastases and matched controls without CNS metastases, assessed by mRNA expression profiling using NGS.
Up to 36 months after baseline

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Association Between Baseline Serum Chemokine Concentrations and CNS Metastases
Time Frame: Up to 36 months after baseline
Assessment of serum concentrations of CX3CL1, CXCL13, and CXCL8 (IL-8) measured at diagnosis using ELISA and their association with subsequent development of CNS metastases during follow-up.
Up to 36 months after baseline

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Predictive Performance of Combined Molecular Biomarker Model for CNS Metastases (ROC Analysis)
Time Frame: Up to 36 months after baseline
Evaluation of predictive accuracy of combined molecular biomarkers (mRNA expression profiles and serum chemokine concentrations) together with clinical-pathological variables using ROC curve analysis.
Up to 36 months after baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Institute of Oncology Ljubljana

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 7, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 19, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 26, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 3, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • OI-AKRA-CNS-2025
  • 0120-315/2025-2711-3 (Other Identifier: Clinical Research Unit, Institute of Oncology Ljubljana)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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