Table 3.

Subgroup analyses of CTCs/DTCs

Subgroup analysis	PFS/DFS						OS
	No. of Studies (sample size)	HR (95 % CI)	Model	P value	P-H	Begg’s test, p value	No. of Studies (sample size)	HR (95 % CI)	Model	P value	P-H	Begg’s test, p value
Total (CTCs and DTCs)	6 (885)	1.99 [1.59, 2.50]	FE	<.0001	0.1047	0.0167	7 (965)	1.94 [1.56 2.40]	FE	<.0001	0.7704	0.2389
Sampling from BM (DTCs)	2 (181)	1.60 [1.17, 2.19]	FE	0.0034	0.4417	1.000	2 (181)	1.89 [1.33, 2.68]	FE	0.0004	0.9687	1.0000
Sampling from PB (CTCs)	4 (704)	2.52 [1.83, 3.48]	FE	<.0001	0.2064	0.3333	5 (784)	1.97 [1.50, 2.58]	FE	<.0001	0.5147	0.0833
Total (IHC and RT-PCR)	5 (756)	1.91 [1.51, 2.40]	FE	<.0001	0.2037	0.0833	6 (818)	1.89 [1.52, 2.36]	FE	<.0001	0.7839	0.7194
Detected DTCs by IHC	3 (397)	1.70 [1.33, 2.19]	FE	<.0001	0.5934	1.0000	3 (397)	1.96 [1.48, 2.60]	FE	0.0004	0.9314	1.0000
Detected CTCs by RT-PCR	2 (359)	3.45 [1.95, 6.24]	FE	<.0001	0.9452	1.0000	3 (439)	1.78 [1.24, 2.54]	FE	0.0017	0.3463	0.3333

FE Fixed-Effects; P-H P-Heterogeneity