Low expression of Mel-18 predicts poor prognosis in patients with breast cancer

Abstract

BackgroundOur previous study suggested that melanoma nuclear protein 18 (Mel-18) acted as a tumor suppressor in human breast cancer. This study was designed to investigate the clinical and prognostic significance of Mel-18 in breast cancer patients. Patients and methodsMel-18 was detected by immunohistochemistry in paraffin-embedded tissues from 287 breast cancer patients, of which 287 were from primary cancer sites, 63 from matched adjacent noncancerous sites, and 35 from metastatic lymph nodes. Differences in Mel-18 expression and clinical characteristics were compared by χ2 test. Prognostic outcomes correlated with Mel-18 were examined using Kaplan–Meier analysis and Cox proportional hazards model. ResultsThe decreased Mel-18 expression is incremental depending upon the magnitude of cancer progression (P < 0.001). Mel-18 was conversely correlated with the pathological classifications (P < 0.001 for T, N, and M classifications, respectively), clinical staging (P < 0.001), and progesterone receptor (P = 0.030). Furthermore, patients with higher level of Mel-18 showed prolonged overall survivals (P < 0.001). The diminished Mel-18 expression may be a risk factor for the patients’ survival (P < 0.001). ConclusionsLower Mel-18 expression is correlated with advanced clinicopathologic classifications and a poor overall survival in breast cancer patients. These findings suggest that Mel-18 may serve as a useful marker in prognostic evaluation for patients.