Examining Ki67 Changes in Breast Cancer Patients Receiving Endocrine Therapy Before Surgery

Differential Changes in Ki67 Between Carriers and Noncarriers of BRCA2 Mutations With Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-negative Breast Cancer Treated With Preoperative Endocrine Therapy

Not applicable Interventional Memorial Sloan Kettering Cancer Center · NCT06127979

This study is testing how a hormone therapy affects a specific marker in postmenopausal women with a certain type of breast cancer before their surgery, and whether this effect is different for those with a BRCA2 mutation compared to those without.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment42 (estimated)
Ages18 Years and up
SexFemale
SponsorMemorial Sloan Kettering Cancer Center Academic / other
Drugs / interventionschemotherapy
Locations1 site (New York, New York)
Trial IDNCT06127979 on ClinicalTrials.gov

What this trial studies

This study investigates the changes in Ki67 expression in postmenopausal women with ER+/HER2- breast cancer who are receiving endocrine therapy for at least two weeks prior to surgery. Participants will be categorized based on their BRCA2 mutation status to compare the effects of the therapy. The study involves core needle biopsies and blood draws to assess the expression levels of Ki67, a marker associated with cell proliferation. The goal is to understand how endocrine therapy impacts Ki67 levels and how this may differ between mutation carriers and non-carriers.

Who should consider this trial

Good fit: Ideal candidates are postmenopausal women aged 18 and older with biopsy-proven stage I-III invasive ER+/HER2- breast cancer scheduled for surgery.

Not a fit: Patients with a history of breast cancer, stage IV disease, or those who are pregnant will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into the effectiveness of endocrine therapy in breast cancer treatment, potentially leading to more personalized treatment approaches.

How similar studies have performed: Other studies have shown promising results in assessing Ki67 expression changes in breast cancer, indicating that this approach has been explored previously.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Postmenopausal women aged ≥18 years with biopsy-proven stage I-III invasive breast cancer that is ER+/HER2-
* Scheduled to undergo upfront surgery
* Eligible for genetic testing in accordance with National Comprehensive Cancer Network guidelines(BRCA2 arm only)

Exclusion Criteria:

* History of breast cancer
* Receipt of ET for risk reduction in the previous 3 months
* Stage IV disease at presentation
* Scheduled to undergo neoadjuvant systemic chemotherapy
* Pregnant

Where this trial is running

New York, New York

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Breast CancerKi67 ExpressionBRCA2 mutationER+/HER2-endocrine therapy23-311
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.