Trial Information

Molecular Predictors of Loco-Regional Recurrence in Node Positive Breast Cancer

OBJECTIVES:

- To evaluate the association between the 21-gene Recurrence Score and risk of
local-regional recurrence (LRR) in node-positive, estrogen receptor- (ER) positive (+)
patients treated with cyclophosphamide and doxorubicin hydrochloride (AC) with or
without paclitaxel in the NSABP-B-28 trial.

- To evaluate the potential for combining the 21-gene Recurrence Score (RS) with
traditional clinico-pathologic factors in order to derive an improved algorithm for
prediction of LRR risk and in order to identify subgroups of ER-positive patients with
1-3 or 4 or more positive nodes who do/do not need post mastectomy chest wall
radiotherapy (XRT) or regional nodal XRT (irrespective of surgical procedure).

- To evaluate whether the 21-gene RS predicts benefit from adding paclitaxel to AC
chemotherapy in reducing risk of LRR, and improving disease-free survival (DFS) and
overall survival (OS) in node-positive, ER-positive patients from NSABP-B-28.

OUTLINE: RNA extracted from paraffin-embedded tissue samples are analyzed for gene
expression profile by Ribogreen assay and RT-PCR. Results are then compared and analyzed
with each patient clinical-pathologic factors, including tumor size, patient age, number of
positive nodes (1-3, 4+), tumor grade, and surgery type (mastectomy or lumpectomy).