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Breast CancerT-REXNCT05634889

The T-REX Trial: Tailored Regional External Beam Radiotherapy in Clinically Node-negative Breast Cancer Patients With 1-2 Sentinel Node Macrometastases.

A study testing De-escalation in people with Breast Cancer, run by Region Skane at 30 sites in 3 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

T-REX is a randomized multicenter, non-inferiority trial. Aim: To evaluate whether regional radiotherapy may safely be omitted in clinically node negative breast cancer patients with one or two sentinel node macrometastases and an estrogen receptor positive, HER2-negative tumor. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Breast Cancer
What is being tested?
De-escalation
Could I receive a placebo?
No, everyone receives an active treatment
How many people
1,350 participants
Where
30 sitesin 3 countries
Study dates
17 Mar 2023to 31 Dec 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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Primary unifocal or multifocal invasive breast cancer T1-T2.
  • Clinically N0.
  • Macrometastasis (>2mm) in 1-2 lymph nodes at sentinel node biopsy.
  • Oral and written consent.
  • Age ≥ 18 years.
  • All resection margins are tumor free (no tumor on ink).
  • Primary tumor ER-positive, HER2-negative.

Who cannot join

  • Regional or distant metastases outside the ipsilateral axilla.
  • Previous RT towards the planned target area, i.e. the ipsilateral chest/lymph nodes.
  • Neoadjuvant systemic therapy.
  • Axillary lymph node dissection or other previous axillary surgery on the affected side.
  • Prior history of invasive breast cancer.
  • Pregnancy.
Show all 10Show fewer
  • Bilateral invasive breast cancer.
  • Contraindication for radiotherapy or systemic treatment.
  • Inability to absorb or understand the contents of the informed consent form; for example, through disability, inadequate language skills or dementia.
  • Other invasive cancer within 5 years prior to breast cancer diagnosis

Trial locations and contacts

30 sites in 3 countries. Contact the study team or a site near you to ask about taking part.

Sara Alkner, Associate professor contact

+4646171000

sara.alkner@med.lu.se

T-REX Clinical Trials Office contact

+4646171000

T_Rex.onkologi@skane.se

30 sites in 3 countries

Sweden18 sites, 18 recruiting

  • Region Västragötaland

    Borås

    Sara Alkner

    Recruiting

  • Region Sörmland

    Eskilstuna, 24751

    Sara Alkner, +46177617, sara.alkner@med.lu.se

    Recruiting

  • Region Gävleborg

    Gävle

    Sara Alkner

    Recruiting

  • Region Västra Götaland

    Gothenburg

    Per Karlsson

    Recruiting

  • Region Halland

    Halmstad

    Sara Alkner

    Recruiting

  • Region Jönköping

    Jönköping

    Sara Alkner

    Recruiting

  • Region Kalmar län

    Kalmar

    Sara Alkner

    Recruiting

  • Region Värmland

    Karlstad

    Sara Alkner

    Recruiting

  • Region Östergötland

    Linköping

    Sara Alkner

    Recruiting

  • Region Skåne

    Lund

    Sara Alkner, sara.alkner@med.lu.se

    Recruiting

  • Region Örebro

    Örebro

    Sara Alkner

    Recruiting

  • Region Västragötaland

    Skövde

    Sara Alkner

    Recruiting

  • Region Stockholm

    Stockholm

    Sara Alkner

    Recruiting

  • Region Västernorrland

    Sundsvall

    Sara Alkner

    Recruiting

  • Region Västerbotten

    Umeå

    Sara Alkner

    Recruiting

  • Region Uppsala

    Uppsala

    Sara Alkner

    Not yet recruiting

  • Region Västmanland

    Västerås

    Sara Alkner

    Recruiting

  • Region Kronoberg

    Vaxjo

    Sara Alkner

    Recruiting

Other trials in Sweden

Norway9 sites, 9 recruiting

  • Ålesund

    Ålesund

    Ingvil Mjaaland

    Recruiting

  • Bergen

    Bergen

    Ingvil Mjaaland

    Recruiting

  • Bodø

    Bodø

    Sara Alkner

    Not yet recruiting

  • Gjövik

    Gjøvik

    Ingvil Mjaaland

    Recruiting

  • Kristiansand

    Kristiansand

    Ingvil Mjaaland

    Recruiting

  • Oslo

    Oslo

    Ingvil Mjaaland

    Recruiting

  • Stavanger

    Stavanger

    Ingvil Mjaaland

    Recruiting

  • Tromsø

    Tromsø

    Ingvil Mjaaland

    Recruiting

  • Trondheim

    Trondheim

    Ingvil Mjaaland

    Recruiting

Other trials in Norway

Finland3 sites, 3 recruiting

  • Helsinki University Hospital

    Helsinki

    Sara Alkner, +46177617, sara.alkner@med.lu.se

    Recruiting

  • Lahti Hospital

    Lahti

    Sara Alkner, +46177617, sara.alkner@med.lu.se

    Not yet recruiting

  • Turku University Hospital

    Turku

    Sara Alkner, +46177617, sara.alkner@med.lu.se

    Not yet recruiting

Other trials in Finland

About this study

Official title: The T-REX-Trial: Tailored Regional External Beam Radiotherapy in Clinically Node-negative Breast Cancer Patients With 1-2 Sentinel Node Macrometastases; an Open, Multicenter, Randomized Non-inferiority Phase 3-trial.

T-REX is a randomized multicenter, non-inferiority trial.

Aim: To evaluate whether regional radiotherapy may safely be omitted in clinically node negative breast cancer patients with one or two sentinel node macrometastases and an estrogen receptor positive, HER2-negative tumor. Leading to an improved quality of life and reduced side effects, without worsening recurrence free survival at five years.

Read more

Intervention: Patients will be randomized to locoregional radiotherapy towards the breast/chestwall and regional lymph nodes vs. to a de-escalated radiotherapy.

In the intervention arm no lymph node irradiation will be given. Radiotherapy is still given to the remaining breast after breast conserving surgery, but no radiotherapy is given after mastectomy.

Sample size: 1350 patients

Primary end-point: Recurrence free survival at five years.

Gene expression analysis: For all patients gene expression analysis for the gene signatures ARTIC, POLAR and OncotypeDX will be performed and related to risk of recurrence and benefit of adjuvant radiotherapy.

Read the detailed description

In this multicenter, prospective randomized trial clinically node-negative breast cancer patients with 1-2 macrometastases in their sentinel lymph node biopsy, and an estrogen receptor positive, HER2-negative tumor, will be randomly assigned to either receive adjuvant locoregional radiotherapy, or no regional radiotherapy.

The main aim is to evaluate whether regional radiotherapy may safely be omitted in patients with limited lymph node metastasis and an estimated low risk of locoregional recurrence. Recurrence free survival after five years is the primary outcome, which for non-inferiority should not worsen more than 4.5 percentage units. Secondary outcomes are locoregional recurrence, regional nodal recurrence, new contralateral BC, distant recurrence free survival, overall survival, non-breast malignancies, cardiac disease, arm morbidity, and health-related quality of life.

Target volumes include:

Standard arm - The remaining breast/chest wall, axillary lymph node levels I-III, the supraclavicular lymph nodes (level IV), the interpectoral lymph nodes and in patients with a medial/central tumor also the internal mammary lymph nodes.

Intervention arm - The remaining breast after breast conserving surgery. No radiotherapy after mastectomy

Conditions
Breast Cancer
Being tested
De-escalation
Keywords
breast cancer, radiotherapy, gene expression analysis, adjuvant breast cancer treatment, regional breast cancer treatment
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • De-escalationRadiation

    No regional radiotherapy. Radiotherapy is given to the remaining breast after breast conserving surgery. Chest wall radiotherapy after mastectomy only in case of wide spread multifocality.

Study groups in NCT05634889
Study groupRoleWhat they receive
StandardNo interventionRadiotherapy to the remaining breast after breast conserving surgery or chest wall after mastectomy, and regional axillary lymph node levels I-IV. Internal mammary nodes are included in the target volume if the tumor has a central/medial localization in the breast.
InterventionExperimentalNo regional radiotherapy. Radiotherapy is given to the remaining breast after breast conserving surgery. Chest wall radiotherapy after mastectomy only in case of wide spread multifocality.
Receives: Radiation: De-escalation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Recurrence Free Survival

    Measured: Five years

Secondary outcomes (8)

  1. Locoregional recurrence

    Measured: Five years

  2. Regional nodal recurrence

    Measured: Five years

  3. New contralateral breast cancer

    Measured: Five years

  4. Distant recurrence free survival

    Measured: Five years

  5. Overall survival

    Measured: Five years

  6. Arm morbidity

    Assessed by questionnaires completed by study participants digitally or on paper between randomization and start of RT, and after 1, 3, and 5 years. The questionnaire used is the Lymphedema Functioning, Disability and Health Questionnaire (Lymph-ICF) developed by Devoogdt in 2011.

    Measured: Five years

  7. Health-related quality of life

    Assessed by the questionnaire EORTC QLQ-C-30 completed by study participants between randomization and RT, and after 1, 3, and 5 years.

    Measured: Five years

  8. Health-related quality of life

    Assessed by the questionnaire BR-23 completed by study participants between randomization and RT, and after 1, 3, and 5 years.

    Measured: Five years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Dec 2022
  2. Study start17 Mar 2023
  3. Primary completion31 Dec 2028 (estimated)
  4. Study completion31 Dec 2033 (estimated)

Resources

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
1,350 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05634889
Sponsor's protocol ID
2022-05093-02
Acronym
T-REX
Status last verified
May 2026
First submitted
18 Nov 2022
Last updated
11 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Data will be made available upon request by the T-REX study group through primary investigator Sara Alkner (sara.alkner@med.lu.se) as specified below.

Publications

  • Alkner S, de Boniface J, Lundstedt D, Mjaaland I, Ryden L, Vikstrom J, Bendahl PO, Holmberg E, Sackey H, Wieslander E, Karlsson P. Protocol for the T-REX-trial: tailored regional external beam radiotherapy in clinically node-negative breast cancer patients with 1-2 sentinel node macrometastases - an open, multicentre, randomised non-inferiority phase 3 trial. BMJ Open. 2023 Sep 26;13(9):e075543. doi: 10.1136/bmjopen-2023-075543.

    PubMed 37751948

Questions about this trial

What is this clinical trial studying?

A study testing De-escalation in people with Breast Cancer, run by Region Skane at 30 sites in 3 countries.

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 7 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 11 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 30 sites in Sweden, Norway, Finland. 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?

Contact Sara Alkner, Associate professor (+4646171000, sara.alkner@med.lu.se), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Recurrence Free Survival (time frame: Five years). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05634889, which also lists 1 linked publication.

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 11 May 2026.

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