Safety of Breast Conserving Treatment in Locally Advanced Breast Cancer Receiving Neoadjuvant Treatment

Study Overview
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Brief Summary
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The study explores the safety of breast conserving treatment (BCT)(defined as complete removal of tumor deposits) after neoadjuvant treatment for locally advanced breast cancer.

Detailed Description
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The standard breast surgical procedure of locally advanced breast cancer in Norway is mastectomy. There is increasing interest in performing breast conserving treatment (BCT) in locally advanced cases after chemotherapy or hormonal treatment - if there is a partial or complete clinical remission. To increase the evidence for the safety (no residual tumor) of such a procedure directly compared to mastectomy without compromising the safety of the treatment, a breast preserving procedure followed by an immediate mastectomy can be performed within a study. It would then be possible to study the margins after the breast preserving procedure as well as the tumor status in the rest of the breast. Patients included in the study will receive neoadjuvant treatment followed by evaluation of the tumor reduction by magnetic resonance imaging (MRI) and selection of BCT candidates. Candidates will be prepared for BCT, and during the surgical procedure, BCT will be performed (as one surgical specimen) followed by immediate removal of the rest of the breast tissue (mastectomy). The BCT specimen and mastectomy specimen will be analysed for residual tumor cells. The tumor removal completeness of the BCT procedure can be evaluated, with comparison to the clinical and primary tumor characteristics, including analysis of the tumor biopsies and imaging before and during the neoadjuvant treatment, for selection of candidates for BCT in the future.

Official Title
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Safety of Breast Conserving Treatment in Locally Advanced Breast Cancer Receiving Neoadjuvant Treatment

Conditions
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Breast Cancer

Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Patients with locally advanced breast cancer (cT3-4c, N0-3) with tumors > 5 cm, as determined by MRI, where the present guidelines include them for neoadjuvant systemic therapy Written informed consent (informed consent document to be approved by the Independent Ethics Committee) prior to study-related procedures and examinations. Female age > 18 years Able to comply with the protocol Histologically confirmed adenocarcinoma of the breast American Society of Anesthesiologist's physical status category 1 or 2 before surgery. Category 1 and 2 includes healthy patients and patients with only mild systemic disease, whereas category 3 includes patients with more serious systemic diseases (but still operable). Exclusion criteria: Inflammatory breast cancer or diffuse locoregional involvement of the skin Stage IV - metastatic disease Locoregional relapse of earlier breast cancer Inability (irrespective of reason) to receive the recommended neoadjuvant treatment, - as decided by the treating physician. American Society of Anesthesiologist's physical status category 4-5

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 1 The presence of viable tumor cells at the margins and in the mastectomy specimen after conducted breast preserving resection followed by mastectomy in the same procedure | The surgical specimens will be analysed after surgery, and the results of these analyses will be the basis for the final end point measurements. | 24 weeks after start of neoadjuvant treatment (at surgery) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tumor molecular marker characteristics related to complete resection by BCT | Tumor molecular marker characteristics, MRI, mammography (Mx) and ultrasound (US) results and clinical parameters in patients with residual tumor cells in the mastectomy specimen compared to those with no tumor cells | 24 weeks after start of neoadjuvant treatment (at surgery) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast cancer, locally advanced, neoadjuvant treatment, breast conserving surgery