A Study of Changes in Ki67 Expression in People With Breast Cancer 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

Status

Recruiting

Phases

Unknown

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06127979

Enrollment

Registered

2023-11-13

Start date

2023-11-06

Completion date

2028-11-01

Last updated

2026-02-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast Cancer

Keywords

Ki67 Expression, BRCA2 mutation, ER+/HER2-, endocrine therapy, 23-311

Brief summary

The researchers are doing this study to look at changes in Ki67 expression after at least 2 weeks of endocrine therapy in people with ER+/HER2- breast cancer undergoing cancer removal surgery. Participants will receive the endocrine therapy before their surgery. The researchers will look at how changes in Ki67 expression compare between participants who are carriers of the BRCA2 mutation and participants who are noncarriers of the BRCA2 mutation.

Interventions

PROCEDUREcore needle biopsy

Pre-Endocrine Therapy core needle biopsy. The pre-treatment research biopsy will require a biopsy marker clip to document that the cancer lesion was biopsied

OTHERblood draw

blood draw

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

OTHER

Masking

NONE

Eligibility

Sex/Gender

FEMALE

Age

18 Years to No maximum

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame	Description
assess the change in Ki67	baseline to at least 2 weeks of endocrine therapy	The change in Ki67 expression on immunohistochemical staining from baseline to at least 2 weeks of ET will be assessed.

Countries

United States

Contacts

CONTACTMinna Lee, MD

leem15@mskcc.org646-888-6898

CONTACTKomal Jhaveri, MD

646-888-5157

PRINCIPAL_INVESTIGATORMinna Lee, MD

Memorial Sloan Kettering Cancer Center

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026