Protein Expression in Predicting Response to Treatment Using Tumor Tissue Samples From Women With Stage I, Stage II, or Stage IIIA Breast Cancer Treated on Clinical Trial SWOG-9313

OBJECTIVES:

- Assess in-situ protein expression of estrogen receptor (ER), progesterone receptor
(PR), HER-2, and p53 by automated quantitative analysis (AQUA™) and multiplexed
analysis at 2 markers per slide using tumor tissue from women with stage I, stage II,
or stage IIIA breast cancer treated on clinical trial SWOG-9313.

- Assess the main effects of ER, PR, HER-2, and p53, as well as interactions to generate
classes formed by clustering of biomarkers, on a large breast cancer tissue microarray
to predict disease-free and overall survival of patients who received high-dose
cyclophosphamide and doxorubicin hydrochloride on clinical trial SWOG-9313.

OUTLINE: This is a multicenter study. Patients are stratified according to receptor status
and menopausal status.

Tumor tissue samples are analyzed by quantitative protein expression analysis (AQUA™, a
fluorescent antibody technique) for estrogen receptor, progesterone receptor, p53 and HER-2.
AQUA™ is used to assess markers individually and as ratios with the use of clustering
algorithms to define reproducible classifications of tissue from patients treated on
SWOG-9313 as a function of molecular classification.

Results of the AQUA™ testing are compared to immunohistochemistry and fluorescent in situ
hybridization (FISH) results obtained on SWOG-9313.

DISEASE CHARACTERISTICS:

- Diagnosis of primary invasive adenocarcinoma of the breast

- Stage I-IIIA disease (T1-3, N0-1, M0)

- Enrolled on clinical trial SWOG-9313

- Tumor tissue available for testing

PATIENT CHARACTERISTICS:

- Not specified

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics