Mitochondrial DNA (mtDNA) is considered a mutation hotspot in various types of tumors, and mitochondrial DNA microsatellite instability (mtMSI) is associated with various cancers. We had previously identified cancer risk-associated MSIs in the D-loop region of mtDNA in renal cell carcinoma (RCC) patients. In the present study, we further investigated the association of MSIs in the non-D-loop region of mtDNA with cancer risk and outcome of RCC. Six microsatellite loci (5892, 8272, 8280, 8281, 8289, 9777) in the non-D-loop of mtDNA were assessed. The CCCCCTCTA at position 8272 was associated with cancer outcome in an overall multivariate analysis (relative risk, 1.599; 95%CI, 1.365-1.872; p < 0.001). mtMSI at position 8272 can therefore be used as an independent prognostic marker for RCC patients.
Keywords: 8272CCCCCTCTA/del; MSI; mtDNA; outcome; renal cell carcinoma; risk.