Table 3.

Summary of subgroup analyses in multiple settings for pooled OS.

Subgroup	Number of studies	Pooled hazard ratio	95% CI	Heterogeneity (p value; I 2)	p value
Detection method
IHC	10	2.00	[1.33, 2.99]	<0.01; 80%	<0.05
qRT-PCR	5	1.80	[1.46, 2.22]	0.53; 0	<0.05
Anatomic structure
Gastrointestinal tract	8	1.62	[1.10, 2.40]	<0.01; 72%	<0.05
Nongastrointestinal tract	7	2.29	[1.91, 2.74]	<0.01; 71%	<0.05
Cancer subtype
CRC	4	2.08	[1.52, 2.85]	0.29; 19%	<0.05
GC	3	1.21	[0.54, 2.75]	<0.01; 84%	0.64
HCC	7	2.29	[1.91, 2.74]	<0.01; 71%	<0.05

Subgroup analyses were performed when there were at least two studies in certain subgroup.