Table 3.

Subgroup analyses of CDH1 promoter methylation in HNSCC

Subgroup	Case		Control		M–H pooled OR	D–L pooled	Heterogeneity
	M	U	M	U	OR (95% CI)	OR (95% CI)	I2 (%)	P-value
Total	450	499	105	450	4.82 (3.64–6.39)	5.94 (3.36–10.51)	64.6	<0.001
Race
African	64	116	4	71	8.52 (3.18–22.83)	6.893 (2.53–18.78)	0	0.42
Caucasian	216	258	66	198	2.80 (1.95–4.02)	2.803 (1.56–5.03)	48.2	0.06
Asian	170	125	35	181	11.84 (6.74–20.79)	13.39 (5.35–33.48)	50.3	0.07
Control types
Autologous	258	358	60	312	5.22 (3.61–7.56)	4.975 (2.83–8.75)	46	0.05
Heterogeneous	192	141	45	138	4.27 (2.76–6.61)	8.69 (2.36–31.96)	78.4	<0.001
Methods
MSP	267	271	79	277	4.55 (3.36–6.15)	5.56 (3.05–10.14)	65.8	<0.001
No MSP	119	173	6	100	6.58 (2.98–14.56)	29.763 (5.72–154.95)	71.8	0.01
Sample size
<60	216	196	62	257	5.44 (3.73–7.94)	5.64 (3.08–10.33)	56.6	0.01
≥60	234	303	43	193	4.20 (2.75–6.41)	10.95 (1.25–96.12)	73.2	0
Published year
<2010	242	288	24	188	9.21 (5.24–16.18)	9.947 (3.77–26.23)	50.8	0.05
≥2010	208	211	81	262	3.56 (2.52–4.91)	4.36 (2.23–8.55)	67.7	0

Note: The pooled OR with 95% CI was calculated by appropriate effect model based on heterogeneity and highlighted in boldface.

Abbreviations: CI, confidence interval; HNSCC, head and neck squamous cell carcinoma; M, methylation; MSP, methylation-specific polymerase chain reaction; OR, odds ratio; U, unmethylation.