This study will examine the relationship of a protein called pAKT to survival of breast cancer patients with one or more positive axillary lymph nodes. Akt plays a role in cell survival, tumor formation, and the development of drug resistance.

The study will use tumor tissue obtained from 2,000 patients enrolled in a National Surgical Adjuvant Breast and Bowel Project study that is evaluating whether adding the drug paclitaxel (Taxol (Registered Trademark)) to a treatment regimen of doxorubicin (Adriamycin (Registered Trademark)) and cyclophosphamide (Cytoxan (Registered Trademark)) improves disease-free survival and overall survival in patients with node-positive breast cancer. The current study will measure levels of pAkt in the tissues and correlate the results with clinical outcome to see if pAkt levels are associated with improved patient survival.

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Taxanes (paclitaxel and docetaxel) have emerged as the most powerful chemotherapeutics in breast cancer over the past decades. The B-28 clinical trial from the National Surgical Adjuvant Breast and Bowel Project (NSABP) assesses the efficacy of adding paclitaxel to the doxorubicin/cyclophosphamide regimen in the treatment of patients with axillary node positive breast cancer. The primary aim of B-28 is to determine whether four cycles of paclitaxel (Taxol (Registered Trademark)) (T) following four cycles of postoperative Doxorubicin (adriamycin (Registered Trademark) (A) and cyclophosphamide (C) will more effectively prolong disease-free survival (DFS) and survival (S) than four cycles of AC alone in patients with operable breast cancer who have one or more histologically positive axillary lymph nodes. The B-28 clinical trial tissue microarray consists of specimens from 2,000 cases enrolled. The tissue microarray set is an ideal platform for evaluating predictive markers of doxorubicin and/or paclitaxel response or resistance.

Akt, a serine/threonine protein kinase regulated by the phosphatidylinositol 3-kinase (PI3K), is of importance in cell survival, tumorigenesis, and recently shown, chemoresistance. It confers survival advantage to cells by transducing signals from growth factor receptors that activate PI3K. The primary aim of this study is to evaluate whether the levels of phosphorylated AKT are associated with disease-free and overall survival in patients with node-positive breast cancer treated with AC and/or AC followed by paclitaxel.

• INCLUSION CRITERIA

The NSABP B-28 trial enrolled women from 1995 to 1998 with operable breast cancer with pathologically positive axillary lymph nodes.