Association of stromal cell gene expression with response to neoadjuvant chemotherapy in locally advanced breast cancer.

Abstract

11129 Background: There is increasing evidence that breast cancer behavior is a reflection of an interactive signaling between the malignant epithelial compartment and the surrounding microenvironment. A high stromal gene expression, characterizing a reactive stroma, was associated with resistance to neoadjuvant chemotherapy, in indirect analysis. Our aim was to detect a stromal cell signature associated with response to neoadjuvant chemotherapy in locally advanced breast cancer, using a direct approach, consisting of stromal cell selection, through laser microdissection. Methods: Twenty one patients treated at Hospital de Câncer de Barretos were included. Patients were diagnosed with invasive ductal carcinoma, except one (lobular invasive carcinoma); median age was 44.5 years; all presented stage III disease; mean tumor dimension was 6.89 cm. Eleven tumors were luminal HER2 negative; 5 HER2 positive [3 ER(+); 2 ER(-)] and 5 triple negative. All patients were submitted to neoadjuvant chemotherapy (4AC fol...