A Phase 2 interventional study of Anastrozole and Letrozole in Breast Cancer and Invasive Breast Cancer, sponsored by Medical College of Wisconsin. Completed at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-04-29.
Sponsored by Medical College of Wisconsin · Phase 2, Interventional, and Treatment
This is an exploratory interventional study that initiates standard-of-care anti-estrogen treatment preoperatively for four weeks.
STUDY RATIONALE: Patients with hormone receptor (HR)+, HER2- node-negative breast cancers generally undergo surgical resection upfront, followed by adjuvant chemotherapy, if needed, in addition to adjuvant endocrine therapy. Because endocrine therapy is primarily delivered in the postoperative setting, the ability to assess the tumor response to this treatment modality is lost and very difficult to assess. This study offers the unique opportunity to assess the responsiveness of breast tumors to endocrine therapy while the tumors are still in vivo by treating patients with endocrine therapy before surgery and assessing molecular changes with treatment. By comparing pre- and post-treatment levels of molecular markers in individual tumors, the team expects to identify predictors of responsiveness to existing agents and identify new candidate therapeutic targets.
PRIMARY OBJECTIVE: The primary objective is to determine the frequency of increased HER family of receptor tyrosine kinases protein expression in tumors, following treatment with neoadjuvant endocrine therapy and their correlation with Ki-67 tumor responses. The team will measure cancer cell protein levels of growth factor receptors of the human epidermal growth factor receptor (HER) family before and after neoadjuvant endocrine therapy. The data will be used to inform a future randomized trial of combined endocrine and the most promising anti-HER targeted therapy.
12,544 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.
This study's enrollment of 37 is below the median of 72 across 9,303 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Medical College of Wisconsin is the lead sponsor of 540 studies on the registry; 120 are open to participants now.
Of its 71 completed or terminated interventional studies of FDA-regulated products, 56 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Adequate organ function with baseline lab values.
Exclusion Criteria:
Once enrolled, patients would be treated with the current standard-of-care endocrine therapy. Choice of endocrine therapy (aromatase inhibitors or tamoxifen) would be decided by medical oncologist, following a review of the patient's medical history and menstrual status. The patient would be treated with endocrine therapy in a neoadjuvant setting for four weeks, with dosing continuing until surgery.
Drug: Anastrozole · Drug: Letrozole · Drug: Exemestane · Drug: Tamoxifen
1 mg once daily.
Also known as: Arimidex
2.5mg once daily.
Also known as: Femara
25 mg once daily.
Also known as: Aromasin
20 mg once daily.
Also known as: Soltamox
Change in Baseline of Cancer Cell Protein Levels of Human Epidermal Growth Factor Receptor (HER) Family Members (HER1-4) Following Neoadjuvant Endocrine Therapy.
ImmunoHistoChemistry (IHC) will be used. The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. If the score is 0 to 1+ (up to 25% of cells stained), it's called "HER2 negative." If the score is 2+ (approximately 50% of cells stained), it's called "borderline." A score of 3+ (approximately 75% or more of cells stained) is called "HER2 positive." Upregulation means increased staining from a prior observation; Downregulation means decreased staining from a prior observation; and No Change means similar staining from a prior observation.
Time frame: At four weeks.
Number of Subjects Who Achieve Complete Radiographic Response.
This will be assessed by World Health Organization (WHO) criteria: * Complete Response (CR): The disappearance of all known disease, based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * Partial Response (PR): A 50% or greater decrease in the product of the bi-dimensional measurements of the lesion (total tumor size), based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * No Change (NC): A 50% decrease in total tumor size cannot be established nor has a 25% increase in the size of the lesion been demonstrated. * Progressive Disease (PD): A 25% or greater increase in the total tumor size of the measurable lesions (calculated on the smallest diameter recorded over time).
Time frame: At four weeks.
Number of Subjects Who Achieve a Partial Radiographic Response.
This will be assessed by World Health Organization (WHO) criteria: * Complete Response (CR): The disappearance of all known disease, based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * Partial Response (PR): A 50% or greater decrease in the product of the bi-dimensional measurements of the lesion (total tumor size), based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * No Change (NC): A 50% decrease in total tumor size cannot be established nor has a 25% increase in the size of the lesion been demonstrated. * Progressive Disease (PD): A 25% or greater increase in the total tumor size of the measurable lesions (calculated on the smallest diameter recorded over time).
Time frame: At four weeks.
| Milestone | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| Started | 37 |
| Completed | 37 |
| Not completed | 0 |
ImmunoHistoChemistry (IHC) will be used. The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. If the score is 0 to 1+ (up to 25% of cells stained), it's called "HER2 negative." If the score is 2+ (approximately 50% of cells stained), it's called "borderline." A score of 3+ (approximately 75% or more of cells stained) is called "HER2 positive." Upregulation means increased staining from a prior observation; Downregulation means decreased staining from a prior observation; and No Change means similar staining from a prior observation.
| Participants | Change From Baseline in Human Epidermal Growth Factor Receptor 1 (HER1) Cell Protein Levels. | Change From Baseline in Human Epidermal Growth Factor Receptor 2 (HER2) Cell Protein Levels. | Change From Baseline in Human Epidermal Growth Factor Receptor 3 (HER3) Cell Protein Levels. | Change From Baseline in Human Epidermal Growth Factor Receptor 4 (HER4) Cell Protein Levels. |
|---|---|---|---|---|
| Upregulation | 1 | 17 | 1 | 1 |
| Downregulation | 0 | 2 | 18 | 18 |
| No Change | 36 | 18 | 18 | 18 |
This will be assessed by World Health Organization (WHO) criteria: * Complete Response (CR): The disappearance of all known disease, based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * Partial Response (PR): A 50% or greater decrease in the product of the bi-dimensional measurements of the lesion (total tumor size), based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * No Change (NC): A 50% decrease in total tumor size cannot be established nor has a 25% increase in the size of the lesion been demonstrated. * Progressive Disease (PD): A 25% or greater increase in the total tumor size of the measurable lesions (calculated on the smallest diameter recorded over time).
| Participants | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| Number of Subjects Who Achieve Complete Radiographic Response. | 0 |
This will be assessed by World Health Organization (WHO) criteria: * Complete Response (CR): The disappearance of all known disease, based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * Partial Response (PR): A 50% or greater decrease in the product of the bi-dimensional measurements of the lesion (total tumor size), based on a comparison between the measurements at baseline and after four weeks of treatment with neoadjuvant therapy. * No Change (NC): A 50% decrease in total tumor size cannot be established nor has a 25% increase in the size of the lesion been demonstrated. * Progressive Disease (PD): A 25% or greater increase in the total tumor size of the measurable lesions (calculated on the smallest diameter recorded over time).
| Participants | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| Number of Subjects Who Achieve a Partial Radiographic Response. | 1 |
Collected over Four weeks.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) | 1/37 (2.7%) | 1/37 (2.7%) | 2/37 (5.4%) |
| Event | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| InfectionInfections and infestations | 1/37 |
| Event | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| ArthralgiaMusculoskeletal and connective tissue disorders | 2/37 |
| HypertensionVascular disorders | 2/37 |
| Age, Categorical(Participants) | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 25 |
| >=65 years | 12 |
| Sex: Female, Male(Participants) | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| Female | 37 |
| Male | 0 |
| Ethnicity (NIH/OMB)(Participants) | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| Hispanic or Latino | 1 |
| Not Hispanic or Latino | 36 |
| Unknown or Not Reported | 0 |
| Race (NIH/OMB)(Participants) | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 1 |
| White | 36 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Region of Enrollment(participants) | Neoadjuvant Endocrine Therapy Treatment (Physician's Choice) |
|---|---|
| United States | 37 |
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Medical College of Wisconsin