Prognostic significance of calcium-sensing receptor in breast cancer

The calcium-sensing receptor (CaSR) is a G-protein coupled receptor that is involved in tumor suppression of cancers. However, its role in breast cancer remains largely unknown. The aim of the study was to investigate the expression of CaSR in breast cancers and to evaluate its prognostic significance. We found that the protein levels of CaSR were significantly reduced in cancer lesion compared with its paired non-tumor tissues. By analyzing the expression of CaSR in a 148 cases of breast cancer tissue microarray (TMA) by immunohistochemistry, we found that patients with lower expression of CaSR were significantly associated with poor overall survival, cause-specific survival, and distant metastasis-free survival. The Cox multivariate analysis showed that CaSR was an independent prognostic significance for both overall survival and cause-specific survival of breast cancer patients. Our data confirmed the tumor suppressor role of CaSR and suggested that CaSR is an independent prognostic indicator of breast cancer.