Somatic mutations in the D-loop of mitochondrial DNA in head and neck squamous cell carcinoma

Abstract

Background: The purpose of this study was to characterize somatic mutations in the D-loop of mitochondrial DNA (mtDNA) and their impact on survival in patients with head and neck cancer.

Methods: Histologically confirmed head and neck cancer and corresponding noncancerous tissues were obtained from 130 patients. The D-loop of mtDNA sequence in noncancerous tissues was compared with that of paired cancer samples and any sequence differences were identified as somatic mutations.

Results: Somatic mutations of the D-loop were observed in 81 patients (62.3%) with head and neck squamous cell carcinoma, and most of them occurred in the poly-C tract. There were no significant differences between the mutation group and nonmutation group in demographic and tumor-related features. Patients with D-loop mutations had better survival (4-year disease-specific survival rate: 70.5% vs 50.8%; p = .0435).

Conclusion: Somatic mutation of D-loop of mtDNA was a potential prognostic factor of head and neck squamous cell carcinoma.

Keywords: head neck cancer; mitochondrial DNA; somatic mutation; squamous cell carcinoma; survival analysis.