Evaluation of the diagnostic value of serum-based proteomics for colorectal cancer

Table 1 Clinical characteristic of individuals in our study

Group	n	Ratio of gender (Male/female)	mean age
CRP	62	1.3:1	58.3
CRC	101	1.1:1	59.7
HC	83	1:1	51.1

CRP: Colorectal polys; CRC: Colorectal cancer; HC: Healthy control.

Table 2 List of standards of matrix-assisted laser desorption/ionization time-of-flight

Substance	Average mass (M + H)+	Resolution	StDeV
Angiotensin II	1047.18	360	10
Angiotensin I	1297.48	365	10
Substance P	1348.64	380	17
Bombesin	1620.86	420	23
ACTH clip 1-17	2094.42	475	22
ACTH clip 18-39	2466.68	540	17
Somatostatin 28	3149.57	580	25
Ubiquitin	4283.45	800	40
Insulin	5734.56	580	25
Cytochrome c	6181.05	560	85
Ubiquitin	8565.89	345	25

Table 3 Comparison of serum protein profiles between colorectal cancer group and healthy control group

Mass (m/z)	DAve	PTTA	PWKW	PAD	Ave1	Ave2
4210.57	536.3	0.00000308	0.00000149	0.066	700.27	1236.57
2932.56	22.98	0.00000635	< 0.000001	0.00721	28.61	51.6
2022.34	282.69	0.0000161	< 0.000001	< 0.000001	309.73	27.04
3192.08	26.53	0.0000333	0.0000105	0.000326	30.96	57.49
3883.65	31.52	0.000476	0.000129	0.00122	46.6	78.12
877.4	3.23	0.000645	0.000129	0.000683	5.93	9.16
1866.09	62.56	0.000826	0.000407	< 0.000001	83.77	21.21
2899.72	13.03	0.000997	0.000189	< 0.000001	38.31	25.28
7772.42	338.93	0.00141	0.00147	0.0503	594.88	933.81
3158.36	53.74	0.00284	0.000264	< 0.000001	62.18	115.92
2272.09	20.34	0.00284	0.0000451	< 0.000001	22.18	42.51
4645.79	22.93	0.00432	0.00483	0.231	57.18	80.11
4092.12	22.14	0.00577	0.0321	0.324	113.17	135.31
1778.9	7.03	0.00739	0.00672	< 0.000001	18.66	11.64
4268.05	27.62	0.00795	0.000333	< 0.000001	69.05	96.67
2952.92	27.19	0.0104	0.0265	0.232	70.78	97.97
3262.98	50	0.0116	0.00564	< 0.000001	69.12	119.11
1897.01	14.98	0.0183	0.0122	< 0.000001	41.59	26.61
2660.37	35.86	0.0197	0.0367	0.286	115.58	151.44

PTTA: P value of t-test; PWKW: P value of Wilcoxon; PAD: P value of Anderson-Darling test.

Table 4 Area under curve values of 19 differential protein profile and carcinoembryonic antigen

DPP	m/z	AUC
P1	877.4	0.714
P2	1778.9	0.595
P3	1866.09	0.687
P4	1897.01	0.640
P5	2022.34	0.843
P6	2272.09	0.705
P7	2899.72	0.746
P8	2932.56	0.783
P9	2952.92	0.589
P10	3158.36	0.759
P11	3192.08	0.811
P12	3262.98	0.751
P13	3883.65	0.642
P14	4092.12	0.655
P15	4210.57	0.805
P16	4268.05	0.744
P17	4645.79	0.617
P18	7772.42	0.714
P19	2660.37	0.666

DPP: Differential protein profile; AUC: Area under curve.

Table 5 Comparison of serum protein profiles between colorectal cancer group and colorectal polys group

Mass	DAve	PTTA	PWKW	PAD	Ave1	Ave2
861.19	33.51	0.000077	0.00000468	< 0.000001	36.09	69.6
4475.16	87.57	0.000186	0.00000468	0.00000185	96.92	184.49
2863.23	37.14	0.000332	0.00073	< 0.000001	88.71	51.57
845.16	4.89	0.000376	0.0000351	0.00000115	7.69	12.59
4210.83	278.83	0.000672	0.00073	0.135	702.87	981.7
2022.52	251.03	0.000672	0.0167	< 0.000001	353.51	102.48
866.41	9.71	0.00209	0.000277	< 0.000001	15.5	25.21
2899.88	12.32	0.00232	0.0000748	< 0.000001	38.41	26.09
1072.04	5.17	0.0032	0.000277	< 0.000001	8.66	13.83
2106.07	12.84	0.00374	0.0000351	< 0.000001	35.74	48.59
4645.62	24.65	0.00634	0.00872	0.0751	65.03	89.68
2953.55	28.69	0.0112	0.0167	0.114	77.95	106.64
2661.25	41.77	0.0134	0.0137	0.0322	121.96	163.73
877.3	6.11	0.0278	0.0000078	< 0.000001	5.81	11.92

PTTA: P value of t-test; PWKW: P value of Wilcoxon; PAD: P value of Anderson-Darling test.

Table 6 Coordinate values and total contribution values of seven peaks in principal component analysis

m/z	1866.45	1945.58	2022.52	2082.82	4210.83	5906.31	7767.55
Loading 1	-0.05	-0.35	-0.2	-0.225	0.32	0.76	0.25
Loading 2	0.17	-0.4	0.81	-0.17	-0.22	0.11	-0.12
Loading 3	-0.015	0.14	-0.1	0.11	0.02	0.36	-0.9
TC	5.45	25.93	24.36	15.52	20.08	44.84	23.07

TC: Total contribution values.

Table 7 The level comparison between classification tree diagnostic model validation and carcinoembryonic antigen, carbohydrate antigen 19-9

Index	Sensitivity (%)	Specificity (%)
Classification tree	81.8	66.7
CEA	55.6	91.3
CA-199	65.4	65.2

CEA: Carcinoembryonic antigen; CA-199: Carbohydrate antigen 19-9.