Trial Information

Levels of Phosphorylated AKT in Patients With Node-Positive Breast Cancer: Correlation With Disease-Free and Overall Survival

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.