Table 5.

DNA methylation levels in primary tumours of CTC-negative and epithelial CTC and mesenchymal CTC-positive BC patients

	DNA methylation levels in primary tumour Mean ± std. deviation (in %)
Genes	CTC-	epi CTC+	mes CTC+	P value*
ADAM23	14.17 ± 12.24a,b	4.56 ± 2.40a	4.92 ± 1.62b	0.001
uPA	13.29 ± 16.37	9.56 ± 8.75	19.33 ± 21.90	0.592
CXCL12	14.45 ± 14.09	7.10 ± 3.00	16.40 ± 15.51	0.287
TWIST1	24.08 ± 18.20	10.00 ± 8.55	24.86 ± 16.34	0.065
SNAI1	5.82 ± 7.14	2.89 ± 1.05c	8.40 ± 7.80c	0.004
SNAI2	7.11 ± 4.95d	3.70 ± 1.34d	6.85 ± 4.90	0.022

*Kruskal-Wallis Test; Adjusted pairwise comparisons: ^aP = 0.003; ^bP = 0.015; ^cP = 0.004; ^dP = 0.018; A statistical two-tailed significance was regarded as P value < 0.05. Abbreviations: BC breast cancer, CTC circulating tumour cell, epi CTC epithelial circulating tumour cells, mes CTC mesenchymal circulating tumour cells