Prognostic value of circulating tumor cells in esophageal cancer

Table 3 Subgroup analyses of the effects of circulating tumor cells on overall survival in esophageal cancer patients

	No. of studies	No. of patients	HR (95%CI)	P value	Heterogeneity
					I2	P value
Region
Asia	6	637	2.46 (1.77-3.40)	< 0.00001	14%	0.33
Non-Asia	2	162	3.74 (1.98-7.05)	< 0.0001	0%	0.36
Curative method
Surgery	5	594	2.81 (1.72-4.58)	< 0.0001	50%	0.09
Non-surgery	3	185	2.70 (1.70-4.30)	< 0.0001	0%	0.95
Detection method
CellSearch	3	228	2.91 (1.78-4.74)	< 0.0001	0%	0.93
RT-PCR	3	354	3.44 (1.42-8.34)	0.006	70%	0.04
Other methods	2	197	2.22 (1.38-3.58)	0.001	0%	0.44