RecruitingInterventional

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

NCT ID: NCT06127979Sponsor: Memorial Sloan Kettering Cancer CenterLast updated: 2026-06-02

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.

Arms & 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

Outcome measures

Primary

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

Eligibility criteria

Sex: FemaleAge: 18 Years and olderHealthy volunteers: No

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

Study locations (1)

Memorial Sloan Kettering Cancer Center (All Protocol Activities)

New York, New York, 10065

Recruiting

Minna Lee, MD · Contact

646-888-6898