Clinical trial · Interventional
Pre-Operative Window of ET to Inform RT Decisions (POWER II)
A Randomized, Phase III Trial of Pre-Operative Window of Endocrine Therapy to Inform Radiation Therapy Decisions in Older Women With Early-Stage Breast Cancer (POWER II)
- 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 Phase III, multisite exploratory study for women ≥ 65 years of age with early stage estrogen receptor positive (ER+) breast cancer. These individuals will be treated randomly assigned to one of two groups: Intervention, treated with 3 months of pre-operative endocrine therapy (pre-ET) OR Control, participants follow standard of care and proceed directly to breast cancer surgery. Both arms will be assessed for tolerance and compliance to the endocrine therapy by patient reported outcome (PRO) measures (patient surveys).
Conditions
Conditions (1)
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 Female | Breast Neoplasm | ONTOLOGY_EXACT | 0.90 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Tamoxifen, Letrozole, Anastrozole, or Exemestane | Drug | — | UNRESOLVED |
Design
Arms and outcomes
Arms (2)
- type
- EXPERIMENTAL
- label
- Intervention Arm
- description
- 90 days of pre-ET (endocrine therapy - tamoxifen or aromatase inhibitor) before Breast Cancer Surgery
- interventionNames
- Drug: Tamoxifen, Letrozole, Anastrozole, or Exemestane
- type
- NO_INTERVENTION
- label
- Control Arm
- description
- Will proceed directly to Breast Cancer Surgery
Primary outcomes (2)
- measure
- Proportion of participants who omit Radiation Therapy (RT) and are non-adherent to Endocrine Therapy (ET)
- timeFrame
- 24 months
- description
- Proportion of participants who omit RT and are non-adherent to ET as measure through the 24-month adjuvant follow-up visit
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 65 Years
Show eligibility criteria text
Inclusion Criteria (summary): * Diagnosis of ER+, PR +/-, and HER2- non amplified invasive breast cancer and clinically negative nodes * ECOG performance status 0-2 * Females, aged ≥ 65 years * Patient is eligible for BCS and opted for BCS * Patient is a candidate for radiation therapy * Patient is a candidate for endocrine therapy (tamoxifen or an aromatase inhibitor) * Ability to take oral medication and be willing to adhere to endocrine therapy for the 3-month period prior to BCS * Agreement to adhere to Lifestyle Considerations (details in protocol) throughout study duration * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study Exclusion Criteria: * Bilateral synchronous breast cancer * Multicentric disease * Prior use of Tamoxifen or aromatase inhibitors * History of ipsilateral breast radiation therapy * Has a known additional malignancy that is progressing and/or requires active treatment with cytotoxic chemotherapy or radiation therapy. Malignancies deemed stable and low risk for complication per investigator's judgment may be allowed after discussion with multi-site PI. * Current or planned use of a strong CYP2D6 inhibitor (e.g., Fluvoxamine, Paroxetine) and is not able to receive an endocrine therapy agent that does not use the CYP2D6 pathway.
References
Publications (0)
Data not yet available