Expression of BRCA1 Protein in Invasive and In Situ Carcinomas and its Relation with Marker of Breast Cancer Stem Cells (CD44) and Prognostic Factors in Breast Cancer Patients

Breast cancer is the most common cancer and the second cause of cancer death among women. Despite recent developments in therapeutic tools about 25% of all the involved cases die annually. The clinical, molecular, and pathologic features of breast cancer in BRCA1 mutation carriers suggest that BRCA1 may function as a stem-cell regulator. The purpose of the current study was to investigate the correlation between BRCA1 protein expression and clinicopathological characteristics, and putative cancer stem cell marker (CD44 (in breast carcinomas. In this experimental study, immunohistochemistry was performed on 156 primary operable breast tumors employing a monoclonal anti-BRCA1 primary antibody. The relation between BRCA1 expression and variations such as age and pathologic features andCD44 was studied by Chi square test. SPSS V.16 was also used for data analysis. Altered BRCA1 expression was significantly associated with high grade and poor prognosis breast tumors (p=0.006). Mutated BRCA1 was also more often seen in early onset breast cancer patients (≤ 40 years) rather than patients over age of 40 (p=0.04). There was also a significant correlation between the BRCA1 andCD44 expression (p= 0.02). Our results indicat ed that mutated BRCA1 expression is a marker of tumor aggressiveness, and its expression related to breast cancer stem markerCD44 in primary breast tumors. These finding support the idea that loss of BRCA1 expression may result in an accumulation of genetically unstable breast stem cells, providing targets for further carcinogenic events.