378 DIAGNOSTIC VALUE OF ANNEXIN A1 EXPRESSION IN MYOEPITHELIAL CELLS FOR THE DETECTION OF BREAST CANCER.

Background Breast cancer is quite an elusive disease; thus, the more information we have about a certain breast sample culture, the better the prognosis. Often times, a biopsy is performed on patient samples and the results tell the physician whether or not the cancers are invasive. However, there is no test that shows if a currently benign tumor will become invasive—and therefore malignant—in the near future. This study has tried to determine whether the annexin A1 is a significant marker in differentiating between benign and premalignant mammary cells. Methods We constructed a paraffin-block microarray consisting of breast tissue from 100 patients. All the samples were taken from the Department of Pathology at Olive View-UCLA Medical Center, and they included sections from normal breast tissue, fibroadenomatous tissue, invasive ductal carcinoma tissue, invasive lobular carcinoma tissue, ductal carcinoma in situ tissue, and lobular carcinoma in situ tissue. In order to analyze the samples, we used rabbit polyclonal annexin A1 antibodies. Results Annexin A1 expression was qualitatively lower in neoplastic cells in the cytoplasmic and nuclear cell compartments. Conclusion The absence of annexin A1 in mammary myoepithelial cells is a useful marker in differentiating between normal and malignant glands in challenging cases of breast cancer.