Annexin A1 expression and its prognostic significance in human breast cancer

Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein and is considered to play an important role in tumorigenesis. However, the correlation between ANXA1 expression and tumor clinicopathological features in patients with breast cancer remains unclear. This study investigated the prognostic value of ANXA1 protein as breast cancer marker. Tissue microarray blocks, containing 20 cases of non-tumor breast tissue, 20 cases of benign breast lesion and 135 cases of breast cancer (107 with lymph node metastasis), were constructed. Expression of ANXA1 in these specimens was analyzed using immunohistochemistry. In non-tumor tissue and benign breast lesions, myoepithelial cells showed strong expression of ANXA1. Negative ANXA1 expression was significantly associated with advanced disease stage (P<0.05), especially pathological-N stage (P<0.01). The patients with loss of ANXA1 expression in tumor tissues showed a significantly worse overall survival compared with positive ones (P<0.05). ANXA1 did not correlate well with estrogen receptor (ER), progesterone receptor (PR) and HER2/neu status. Moreover, the level of ANXA1 expression in lymph node metastases was higher than corresponding primary breast cancer. These results suggest that ANXA1 may play a multifaceted role in breast cancer development, progression, and metastases.