Neoadjuvant Tamoxifen in Locally Advanced Breast Cancer in a Low/Middle Income Country

Study Overview
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Brief Summary
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This study evaluates the feasibility and efficacy of neoadjuvant tamoxifen for patients with locally advanced hormone receptor positive breast cancer in a low/middle income country.

Detailed Description
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This is a single arm feasibility study of neoadjuvant tamoxifen for locally advanced hormone receptor positive breast cancer in a low-resource setting in a middle-income country (Guatemala). Patients will be treated with tamoxifen for four to six weeks, then have an on-treatment biopsy to assess Ki-67. If Ki-67 is less than or equal to 10%, the patient will continue on tamoxifen for a total of 4 months; if Ki-67 is greater than 10% or there is clinical progression, patients will be taken off study. The study will evaluate the proportion of patients treated with four months of tamoxifen who undergo definitive surgery and the clinical and pathologic response rates.

Official Title
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Neoadjuvant Endocrine Therapy in Locally Advanced Hormone Receptor Positive Breast Cancer in a Low-Resource, Middle-Income Setting (Guatemala)

Conditions
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Breast Cancer, Breast Neoplasms

Intervention / Treatment
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* Drug: Tamoxifen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient evaluated and treated at INCAN Patients must provide informed consent Patient must be ≥ 18 years of age. Life expectancy ≥ 6 months Clinical locally advance breast cancer (Stage IIB or III) Pathologically confirmed diagnosis of estrogen receptor (ER)-positive or progesterone receptor (PR)-positive breast cancer with ER or PR Allred Score > 4 Patient must have an ECOG Performance Status of 0-2 Patients must be able to swallow and retain oral medication Exclusion Criteria: Patient must not have received any prior chemotherapy, radiation therapy, or biologic therapy for invasive breast cancer within the past five years Patient must not be pregnant or nursing Patient must not have had any prior malignancy except for adequately treated basal cell (or squamous cell) skin cancer, in situ cervical cancer or other cancer for which the patient has been disease-free for five years. Women of childbearing age unable or unwilling to use contraception

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tamoxifen<br>Tamoxifen 20mg by mouth daily | Drug: Tamoxifen<br>* Tamoxifen 20mg by mouth daily<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants Who Were Successfully Accrued in the Study, as a Measure of Feasibility | Feasibility is defined as the ability to recruit the stated number of patients and fifty percent of participants completing the trial. Completing the trial is defined as reaching surgery if they are a responder to tamoxifen or obtaining the six week biopsy specimen if they are a non-responder. | 4-6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Definitive Surgery in Responders to Neoadjuvant Tamoxifen | Rate of definitive surgery after 4 months of neoadjuvant tamoxifen therapy in patients who were deemed to be responders to neoadjuvant tamoxifen (Ki67 < or = 10% after 4-6 weeks on neoadjuvant tamoxifen therapy) | 4-6 months | 
| Ki67 Suppression Rate at 4-6 Weeks in Patients Who Underwent an On-treatment Biopsy | Result is the number of participants who had Ki67 suppression (< or = 10%) after 4-6 weeks of neoadjuvant tamoxifen out of patients who underwent an on-treatment biopsy. | 4-6 weeks | 
| Overall Clinical Response Rate | Clinical response rate was assessed by palpation after 4 months of tamoxifen. Complete response was defined as no palpable primary tumor on clinical examination and lymph nodes < 10 mm. Partial response was defined as at least 30% decrease in the sum of the diameters compared to baseline sum of diameters. The overall clinical response was the sum of the complete clinical response and partial clinical response. | 4-6 months | 
| Pathologic Complete Response | Pathologic complete response was defined as no residual tumor at the primary site or the axillary lymph nodes at the time of surgery. | 4-6 months | 
| Breast Conserving Therapy | The rate of breast conservation surgery (as opposed to mastectomy) after 4 months of neoadjuvant tamoxifen therapy in patients who were deemed to be responders to neoadjuvant tamoxifen (Ki67 < or = 10% after 4-6 weeks on neoadjuvant tamoxifen therapy). | 4-6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast neoplasms, Breast cancer, Locally advanced breast cancer, Neoadjuvant endocrine therapy, Tamoxifen, Low and middle income country