Prognostic Significance of Mitochondrial Transcription Factor A Expression in Patients with Right- or Left-sided Colorectal Cancer

BACKGROUND/AIM: Mitochondrial transcription factor A (mtTFA) is necessary for both the transcription and maintenance of mitochondrial DNA (mtDNA). The present study investigated the clinical significance of mtTFA in patients with right- and left-sided colorectal cancer (CRC). PATIENTS AND METHODS: Surgical specimens from 237 CRC patients were immunohistochemically stained with polyclonal anti-mtTFA antibody. The relationships among the mtTFA expression, clinicopathological factors and prognosis were evaluated. RESULTS: Thirty-five (60.3%) of 58 right-sided CRC patients and 82 (45.8%) of 179 left-sided CRC patients showed high mtTFA expression. The mtTFA expression significantly correlated with lymph node metastasis, distant metastasis, the TNM stage and lymphatic invasion in left-sided CRC patients and did not correlate with any factors in right-sided CRC patients. Univariate and multivariate analyses revealed the mtTFA expression to be a significant prognostic factor in left-sided CRC patients but not in right-sided CRC patients. CONCLUSION: These results suggest that a high mtTFA expression is a useful marker for tumor progression and a poor prognosis in left-sided CRC patients.