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

Patients and methods: Mel-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 chi(2) test. Prognostic outcomes correlated with Mel-18 were examined using Kaplan-Meier analysis and Cox proportional hazards model. Results: The 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). Conclusions: Lower 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.