Diagnostic value of circular free DNA for colorectal cancer detection

Table 1 General clinical characteristics of the subjects

Characteristics	CRC (training)	HC (training)	CRC (validation)	HC (validation)
Number	101	195	62	100
Age, yr
Mean	58	53	57	55
Range	29-81	33-57	33-74	34-67
Sex
Male	60	116	37	64
Female	41	79	25	36
TNM stage
T1	11		11
T2	27		21
T3	44		7
T4	19		23

CRC: Colorectal cancer; HC: Healthy control; TNM: Tumor node metastasis.

Table 2 Comparison of the four markers between the healthy control group and colorectal cancer group

Indicator	HC (n = 195)	CRC (n = 101)	F	Sig	P value
NDUFB7	1.54 (0.94, 2.31)	2.10 (1.29, 3.08)	0.15	0.70	0.60
CAMK1D	9.71 (6.38, 18.25)	70.39 (35.26, 155.57)	34.24	< 0.01	< 0.01
PIK3CD	297.11 (232.76, 374.69)	333.22 (259.40, 417.90)	10.47	< 0.01	0.03
PSEN2	5.48 (4.04, 7.21)	8.69 (6.00, 11.67)	5.89	0.02	< 0.01

CRC: Colorectal cancer; HC: Healthy control.

Table 3 Evaluation of the diagnostic value of three markers exhibiting statically significant differences between the healthy control group and colorectal cancer group

Indicator	AUC	SD	P value	95%CI
				Lower	Upper
CAMK1D	0.935	0.015	< 0.001	0.907	0.964
PSEN2	0.740	0.031	< 0.001	0.678	0.801
PIK3CD	0.582	0.036	0.021	0.511	0.653

AUC: Area under the curve.

Table 4 Univariate and multivariate logistic regression of CAMK1D and PSEN2

Indicator	B	SE	Wals	P value	Exp (B)	95%CI
						Lower	Upper
CAMK1D	0.560	0.137	16.781	< 0.001	1.751	1.339	2.289
PIK3CD	0.071	0.011	41.382	< 0.001	1.074	1.051	1.097

Table 5 Multivariate logistic regression of CAMK1D and PSEN2

Indicator	B	SE	Wals	P value	Exp (B)	95%CI
						Lower	Upper
CAMK1D	0.125	0.039	10.400	0.001	1.133	1.050	1.222
PIK3CD	-0.002	0.004	0.208	0.648	0.998	0.990	1.006