Table 1.

Associations between WB-mtDNA variant numbers and DMFS

	n	HR (95% CI)	p
TVN	44	0.935 (0.878–0.996)	0.037
TVN without haplogroup-specific variants	44	1.076 (0.862–1.344)	0.515
TVN without AV	44	0.918 (0.849–0.992)	0.031
CRVN	44	0.912 (0.830–1.002)	0.055
CRVN without AV	44	0.875 (0.768–0.997)	0.046
HVR1 (C16024-C16569) variant number	44	0.998 (0.807–1.233)	0.982
HVR1 variant number without AV	44	1.002 (0.801–1.254)	0.983
HVR2-3 (C1-C576) variant number	44	0.692 (0.517–0.928)	0.014
HVR2-3 variant number without AV	44	0.704 (0.520–0.953)	0.023
Total AV number	44	0.845 (0.682–1.047)	0.124

HR below 1 indicates favourable DMFS with higher number of mtDNA base variants, from Cox proportional hazard models

AV ancestral variants, C control region, CI confidence interval, CRVN coding region variant number, DMFS distant metastasis-free survival, HR hazard ratio, HVR hypervariable region (the C region’s base sites within the HVRs are given in brackets), TVN total variant number, WB-mtDNA whole blood mitochondrial DNA