Neoplasms

Skin and Connective Tissue Diseases

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Breast Neoplasms

Breast Diseases

Skin Diseases

Radiotherapy 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.

No regional radiotherapy. Radiotherapy is given to the remaining breast after breast conserving surgery, while mastectomy patients do not receive any radiotherapy at all.

No regional radiotherapy. Radiotherapy towards the remaining breast after breast conserving surgery, but no radiotherapy at all after mastectomy.

De-escalation

Sara Alkner, Associate professor

T-REX Clinical Trials Office

Per Karlsson

Kirsten Björlinger

Barbara Wysocka

Sara Alkner

Camilla Wendt

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.

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 in collaboration with Exact Sciences, and related to risk of recurrence and benefit of adjuvant radiotherapy.

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

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

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.

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.

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.

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

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

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization	Link
The T-REX Trial: Tailored Regional External Beam Radiotherapy in Clinically Node-negative Breast Cancer Patients With 1-2 Sentinel Node Macrometastases.	NCT05634889	Breast Cancer	De-escalation	18 Years -	Region Skane
The T-REX Trial: Tailored Regional External Beam Radiotherapy in Clinically Node-negative Breast Cancer Patients With 1-2 Sentinel Node Macrometastases.	NCT05634889	Breast Cancer	De-escalation	18 Years -	Region Skane

Spots Global Cancer Trial Database for regional breast cancer treatment