Biomarkers in Predicting Response to Tamoxifen and Letrozole in Postmenopausal Women With Primary Breast Cancer Treated on Clinical Trial CAN-NCIC-MA17

Study Overview
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Brief Summary
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RATIONALE: Studying samples of tumor tissue from patients with cancer in the laboratory may help doctors learn more about changes that occur in DNA and identify biomarkers related to cancer. It may also help doctors predict how well patients respond to treatment. PURPOSE: This laboratory study is looking at biomarkers that may predict response to tamoxifen and letrozole in postmenopausal women with primary breast cancer treated on clinical trial CAN-NCIC-MA17.

Detailed Description
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OBJECTIVES: Assess the prognostic utility of the MGH 2-gene and the GHI 21-gene expression signatures in postmenopausal women with primary breast cancer treated with tamoxifen followed by either placebo or letrozole on clinical trial CAN-NCIC-MA17. Assess the ability of the MGH 2-gene and the GHI 21-gene expression signatures to predict responsiveness to letrozole. Compare the prognostic utility of quantitative immunofluorescence vs standard immunohistochemistry of estrogen receptor, progesterone receptor, HER-2, tumor aromatase, cyclooxygenase-2, GATA-3, and NAT-1 in these patients. Assess the ability of quantitative immunofluorescence and standard immunohistochemistry of these proteins to predict responsiveness to letrozole in these patients. Use gene discovery from formalin-fixed, paraffin-embedded tumor specimens to identify novel gene expression profiles that may predict outcome and responsiveness to letrozole in these patients. OUTLINE: This is a controlled study. Formalin-fixed, paraffin-embedded breast tumor tissue samples are analyzed for MGH 2-gene and GHI 21-gene expression signatures using real-time quantitative polymerase chain reaction. Immunohistochemistry and immunofluorescence are used for analysis of estrogen receptor, progesterone receptor, HER-1 and -2, aromatase, GATA-3, NAT-1, and cyclooxygenase-2. Microarray hybridization is used to identify novel gene expression signatures. PROJECTED ACCRUAL: A total of 957 specimens will be accrued for this study.

Official Title
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Quantitative Protein and Gene Expression Biomarkers of Tamoxifen and Letrozole Recurrence in the NCIC CTG MA.17 Cohort

Conditions
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Breast Cancer

Intervention / Treatment
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* Genetic: microarray analysis
* Genetic: polymerase chain reaction
* Genetic: protein expression analysis
* Other: diagnostic laboratory biomarker analysis
* Other: fluorescent antibody technique
* Other: immunohistochemistry staining method
* Other: immunologic technique


Participation Criteria
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Eligibility Criteria
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DISEASE CHARACTERISTICS: Histologically or cytologically confirmed primary invasive breast carcinoma resected at time of original diagnosis Treated on clinical trial CAN-NCIC-MA17 Hormone receptor status: Estrogen or progesterone receptor positive tumor PATIENT CHARACTERISTICS: Female Postmenopausal PRIOR CONCURRENT THERAPY: Not specified
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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Genetic: microarray analysis|nan|
|Genetic: polymerase chain reaction|nan|
|Genetic: protein expression analysis|nan|
|Other: diagnostic laboratory biomarker analysis|nan|
|Other: fluorescent antibody technique|nan|
|Other: immunohistochemistry staining method|nan|
|Other: immunologic technique|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prognostic utility of the MGH 2-gene and the GHI 21-gene expression signatures |  |  | 
| Ability of the MGH 2-gene and the GHI 21-gene expression signatures to predict responsiveness to letrozole |  |  | 
| Prognostic utility of quantitative immunofluorescence vs standard immunohistochemistry of estrogen receptor, progesterone receptor, HER-2, tumor aromatase, cyclooxygenase-2, GATA-3, and NAT-1 |  |  | 
| Ability of quantitative immunofluorescence and standard immunohistochemistry of these proteins to predict responsiveness to letrozole |  |  | 
| Novel gene expression profiles that may predict outcome and responsiveness to letrozole |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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stage IA breast cancer, stage IB breast cancer, stage II breast cancer, stage IIIA breast cancer, estrogen receptor-positive breast cancer, progesterone receptor-positive breast cancer