Association of complement components with risk of colorectal cancer: A systematic review and meta-analysis

Table 1 Meta-analysis of complement component proteins and clinicopathological features of colorectal cancer patients

Clinicopathological feature	Reference	No. of studies	Model	Pooled RR (95%CI)	P value	Heterogeneity
						I2 (%)	P value
CD55
Age (> 60 years old)	High vs low expression	2	Fixed	1.16 (0.92-1.45)	0.21	0	0.58
Sex (male)	High vs low expression	3	Fixed	1.09 (0.90-1.33)	0.36	0	0.51
Lymph node metastasis	High vs low expression	3	Fixed	1.30 (1.03-1.63)	0.03	0	0.70
Differentiation	High vs low expression	3	Fixed	1.09 (0.93-1.29)	0.28	0	0.95
T3 + T4	High vs low expression	3	Fixed	1.11 (0.99-1.24)	0.08	0	0.95
M1	High vs low expression	3	Random	1.52 (0.43-5.43)	0.52	86	< 0.001
CD59
Age (> 60 years old)	High vs low expression	2	Fixed	0.88 (0.66-1.15)	0.34	0	0.66
Sex (male)	High vs low expression	2	Fixed	0.85 (0.68-1.06)	0.14	0	0.81
Lymph node metastasis	High vs low expression	2	Fixed	1.53 (1.12-2.08)	0.007	53	0.14
CD46
Age (> 60 years old)	High vs low expression	2	Fixed	1.15 (0.86-1.52)	0.35	0	0.98
Sex (male)	High vs low expression	2	Fixed	0.87 (0.68-1.10)	0.24	0	0.63
Lymph node metastasis	High vs low expression	2	Random	0.81 (0.39-1.66)	0.56	83	0.01
Differentiation	High vs low expression	2	Fixed	1.30 (1.04-1.63)	0.02	0	0.69
T3 + T4	High vs low expression	2	Random	0.75 (0.35-1.60)	0.46	80	0.03

RR: Risk ratio; CI: Confidence interval; CD: Cluster of differentiation.

Table 2 Potential sources of heterogeneity for association between positive expression of complement component proteins and colorectal cancer by region

Subgroup	Study number	Risk ratio (95%CI)	I2	P value
CD55
Asian	2	16.88 (8.49-33.52)	65%	< 0.001
Non-Asian	2	1.49 (0.19-11.97)	88%	0.71
CD59
Asian	2	6.63 (4.06-10.82)	63%	< 0.001
Non-Asian	3	1.97 (1.22-3.18)	0%	0.006
CD46
Asian	2	3.66 (1.75-7.64)	92%	0.040
Non-Asian	2	4.37 (1.95-9.78)	0%	< 0.001

CI: Confidence interval; CD: Cluster of differentiation.

Table 3 Egger’s test for complement components

	Studies	Egger’s test
		t	Bias	P value
CD46	4	1.34	2.34	0.311
CD55	4	1.02	6.15	0.414
CD59	5	-0.09	-1.15	0.931
C3	3	-0.44	-9.27	0.734

CD: Cluster of differentiation; C3: Complement component 3.