A Study of Changes in Ki67 Expression in People With Breast Cancer Receiving Endocrine Therapy Before Surgery
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.
Conditions studied
Breast Cancer
About this study
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
- Procedure: core 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
- Other: blood draw — blood draw
Primary outcomes
- assess the change in Ki67 (baseline to at least 2 weeks of endocrine therapy)
Eligibility information
Study locations
- Memorial Sloan Kettering Cancer Center (All Protocol Activities), New York, New York 10065 United States
Source: ClinicalTrials.gov. Record last refreshed by Varda Clinical: 2026-09-27.