Clinical trial · Interventional
Partial Breast Irradiation Without Sentinel Lymph Node Biopsy in Low-Risk Early Breast Cancer
A Phase III Randomized Trial of Partial Versus Whole Breast Radiotherapy in Clinically Node-Negative Early Breast Cancer Omitting Sentinel Lymph Node Biopsy (APROOB Trial)
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
This is a multicenter, randomized, phase III non-inferiority trial in women aged 40 years or older with clinically node-negative (cN0), pathologically pT1 (≤2 cm), grade 1-2, lymphovascular invasion (LVI)-negative invasive breast cancer treated with breast-conserving surgery (BCS) in whom sentinel lymph node biopsy (SLNB) was omitted (pNx). Eligible patients are randomized 1:1 to partial breast irradiation (PBI) or whole breast irradiation (WBI). The primary aim is to determine whether PBI is non-inferior to WBI with respect to the 5-year recurrence-free survival (RFS) rate. Secondary aims include comparison of axillary recurrence, overall survival, locoregional recurrence, treatment-related toxicity, and quality of life between arms.
Conditions
Conditions (3)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Breast Cancer | Malignant Breast Neoplasm | CURATED_EXACT | 0.92 |
| Early-Stage Invasive Breast Carcinoma | — | UNRESOLVED | — |
| Node-negative Breast Cancer | — | UNRESOLVED | — |
Interventions
Interventions (2)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Partial Breast Irradiation | Radiation | — | UNRESOLVED |
| Whole Breast Irradiation | Radiation | — | UNRESOLVED |
Design
Arms and outcomes
Arms (2)
- type
- ACTIVE_COMPARATOR
- label
- Whole Breast Irradiation (WBI)
- description
- Whole breast irradiation using 3D conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT).
- interventionNames
- Radiation: Whole Breast Irradiation
- type
- EXPERIMENTAL
- label
- Partial Breast Irradiation (PBI)
- description
- Partial breast irradiation targeting the tumor bed with margin, using 3D-CRT or IMRT, sparing the remainder of the breast.
- interventionNames
- Radiation: Partial Breast Irradiation
Primary outcomes (1)
- measure
- 5-Year Recurrence-Free Survival Rate
- timeFrame
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 40 Years
Show eligibility criteria text
Inclusion Criteria: * Female ≥40 years with histologically confirmed unilateral invasive breast cancer. * No suspicious nodal metastasis on preoperative axillary ultrasound (cN0). * Single lesion in the affected breast on preoperative breast ultrasound and mammography. * Treated with breast-conserving surgery with pathologically negative margins for the invasive tumor. * Sentinel lymph node biopsy not performed at surgery (pNx). * Maximum diameter of invasive tumor ≤2 cm on final pathology (pT1). * Histologic grade 1 or 2. * Signed informed consent prior to enrollment. Exclusion Criteria: * History of malignancy other than breast cancer within 5 years (except adequately treated non-melanoma skin cancer, or carcinoma in situ excluding breast carcinoma in situ). * Preoperative diagnosis of carcinoma in situ without axillary nodal sampling, subsequently diagnosed as invasive breast cancer on final pathology with SLNB omitted. * Lymphovascular invasion present (LVI+). * Multifocal or multicentric tumor in the same breast confirmed radiologically or pathologically. * Bilateral or inflammatory breast cancer. * Prior radiotherapy to the breast or thorax. * Confirmed pathogenic or likely pathogenic variant in a hereditary breast cancer gene (including BRCA1/2). * Recurrent breast cancer.
References
Publications (0)
Data not yet available