High copy number of mitochondrial DNA predicts poor prognosis in patients with advanced stage colon cancer.

INTRODUCTION: The aim of this investigation was to determine whether alterations in mitochondrial DNA (mtDNA) copy number in colon cancer were associated with clinicopathological parameters and postsurgical outcome.

METHODS: By quantitative real-time PCR assay, the mtDNA copy number was detected in a cohort of colon cancer and matched adjacent colon tissues (n = 162).

RESULTS: The majority of patients had higher mtDNA content in colon cancer tissues than matched adjacent colon tissues. Moreover, high mtDNA content in tumor tissues was associated with larger tumor size, higher serum CEA level, advanced TNM stage, vascular emboli, and liver metastases. Further survival curve analysis showed that high mtDNA content was related to the worst survival in patients with colon cancer at advanced TNM stage.

CONCLUSIONS: High mtDNA content is a potential effective factor of poor prognosis in patients with advanced stage colon cancer.