Trial Information

Evaluation of the Co-Expression of the Cancer Stem Cell Marker ALDH1 and of HER2 as a Predictor of Adjuvant Trastuzumab Response in Breast Cancers of Women in NSABP B31

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).