Table 2. Meta-analysis of the Survivin −31C/G polymorphism and cancer risk association.

		Sample size			Test of association				Test of heterogeneity
Polymorphism	Study	Case	Control	Na	OR (95% CI)	Z	P-value	Modelb	χ2	Pc	I2 (%)
CC vs GG	Overall	1897	2018	14	1.59 (1.20–2.10)	3.20	0.001	R	44.27	<0.001	72.9
Ethnicity
	Asian	1280	1353	7	1.67 (1.16–2.40)	2.73	0.006	R	27.74	<0.001	78.4
	European	578	636	6	1.47 (0.85–2.55)	1.36	0.173	R	14.59	0.006	72.6
Cancer type
	Gastric cancer	197	166	3	2.20 (0.71–6.88)	1.36	0.173	R	10.51	0.005	81.0
	Esophageal cancer	253	271	2	1.32 (0.51–3.46)	0.57	0.568	R	6.34	0.012	84.2
GC vs GG	Overall	2514	3134	14	1.08 (0.90–1.28)	0.80	0.421	R	25.69	0.012	53.3
Ethnicity
	Asian	1656	2072	7	1.32 (0.87–1.48)	0.92	0.358	R	18.40	0.005	67.4
	European	820	1013	6	1.06 (0.87–1.29)	0.60	0.548	F	6.24	0.182	35.9
Cancer type
	Gastric cancer	252	277	3	1.06 (0.74–1.53)	0.34	0.736	F	4.66	0.097	57.1
	Esophageal cancer	369	415	2	0.99 (0.74–1.31)	0.09	0.925	F	0.00	0.947	0.0
CC/GC vs GG	Overall	3485	3964	14	1.23 (1.00–1.51)	2.00	0.045	R	39.23	<0.001	69.4
Ethnicity
	Asian	2388	2714	7	1.32 (0.99–1.78)	1.86	0.063	R	26.18	<0.001	77.1
	European	1050	1193	6	1.18 (0.85–1.65)	0.98	0.328	R	11.97	0.018	66.6
Cancer type
	Gastric cancer	363	344	3	1.38 (0.62–3.08)	0.79	0.429	R	9.48	0.009	78.9
	Esophageal cancer	471	518	2	1.06 (0.81–1.38)	0.39	0.696	F	0.65	0.421	0.0
CC vs GG/GC	Overall	3485	3964	14	1.51 (1.23–1.85)	3.90	<0.001	R	33.29	0.001	64.0
Ethnicity
	Asian	2388	2714	7	1.50 (1.17–1.91)	3.24	0.001	R	18.96	0.004	68.4
	European	1050	1193	6	1.44 (0.91–2.29)	1.55	0.120	R	12.45	0.014	67.9
Cancer type
	Gastric cancer	363	344	3	2.06 (0.91–4.66)	1.74	0.083	R	7.06	0.029	71.7
	Esophageal cancer	419	518	2	1.32 (0.50–3.50)	0.57	0.571	R	8.30	0.004	87.9

^aNumber of comparisons.

^bRandom-effects model (R) was used when P-value for heterogeneity test <0.05; otherwise, fix-effects model (F) was used.

^cP-value of Q-test for heterogeneity test.

Bold values indicate significant difference.