RATIONALE: Studying samples of 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. PURPOSE: This research trial studies biomarkers as a predictor of response to trastuzumab in samples from patients with breast cancer previously treated in the NSABP-B-31 trial.
OBJECTIVES: Primary * To determine if stem cellness identifies a poor prognostic subgroup of women with early-stage breast cancer who have been uniformly treated with either adjuvant doxorubicin hydrochloride \& cyclophosphamide followed by paclitaxel (the "control arm" of B31), or the same chemotherapy plus trastuzumab. Secondary * To conduct exploratory analyses to assess, to the extent possible, if co-localization of stem cellness, as determined by ALDH1 positivity, and HER2 identifies a group of patients previously considered to have HER2-negative cancers (using classical definitions) who benefit from adjuvant trastuzumab. OUTLINE: Archived breast cancer stem cells samples and terminally differentiated cells from tissue samples are analyzed for HER2 and ALDH1 expression by dual-staining quantitative immunofluorescence using Automated Quantitative Analysis (AQUA) , IHC, and fluorescence in situ hybridization (FISH).
Study Type
OBSERVATIONAL
Enrollment
1,874
ALDH1 expression (percentage of stem cells within the tumor) and association with outcomes regardless of HER2 staining
Time frame: approximately 4 years
HER2 expression in cells with stem cell-like properties as a determinant of aggressiveness and response to trastuzumab in the adjuvant setting
Time frame: approximately 4 years
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