Ecotropic virus integration-1 and calreticulin as novel prognostic markers in triple-negative breast cancer: A retrospective cohort study

Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer, for which no specific targete d therapy is currently available. The present study aimed to examine the associations of ecotropic virus integration site 1 (EVI-1) and calreticulin (CRT) with other clinicopathological variables and the prognosis of patients with TNBC. The present retrospective cohort study reviewed the medical records of patients with TNBC treated in the Affiliated Hospitals of Jinzhou Medical University between January 2010 and June 2015. The protein expression levels of EVI-1 and CRT in tumor samples obtained from the patients were examined by immunohistochemical analysis. Univariate and multivariate regression analyses were used to identify associations between clinical characteristics and disease-free survival (DFS) or overall survival (OS). Kaplan-Meier analysis was performed to observe the survival condition (DFS/OS) according to EVI-1 and CRT expression. A total of 88 TNBC patients were included in the present study. Tumor tissues in 52 (59.1%) patients were EVI-1 positive, and tumor tissues in 64 (72.7%) patients were CRT-positive, and these rates were significantly higher compared with those in the corresponding paracancerous tissues (P<0.05). Multivariate analysis revealed that EVI-1 and CRT expression levels were independent variables associated with OS and DFS, and high expression of both CRT and EVI-1 was significantly associated with decreased OS and DFS compared with the other subgroups (low EVI-1/low CRT expression, low EVI-1/high CRT expression and high EVI-1/low CRT expression) of patients with TNBC. EVI-1 and CRT expression in TNBC was significantly correlated with poor outcome. Evaluation of the EVI-1 and CRT status may provide insight into prognosis prediction for patients with TNBC.