Prognostic significance of MCM6 expression in gastrointestinal stromal tumor

Minichromosome maintenance (MCM) proteins are essential for the initiation of DNA replication and they are prognostic markers in various human cancers. The aim of this study was to investigate the role of the MCM6 protein in gastrointestinal stromal tumor (GIST) and its clinical and prognostic significance. We evaluated MCM6 expression in 211 GIST samples using immunohistochemistry. We used the receiver operating characteristic curve (ROC) to identify optimal cut-off values. High MCM6 expression was associated with tumor size, mitosis, tumor necrosis, presence of recurrence/metastasis, and the National Institute of Health (NIH) and Armed Forces Institute of Pathology (AFIP) malignant risk criteria. Patients with high MCM6 expression had significantly shorter overall survival (OS) and disease-free survival (DFS) than those with low MCM6 expression. Univariate analysis indicated that tumor size, mitosis, AFIP and NIH malignant risk criteria, and high MCM6 expression were significantly associated with poor OS and DFS. High MCM6 expression and high-risk group categorization based on the NIH criteria were independent prognostic factors for OS and DFS. High MCM6 expression is significantly associated with tumor progression and aggressiveness and is an independent factor for shorter survival in GIST patients. MCM6 expression could be a predictive biomarker for tumor aggressiveness as well as a treatment target.