|
Subgroup
|
Number of studies
|
Number of patients
|
Pooled HR (95% CI)
|
p value
|
Heterogeneity
|
Meta-regression
|
|---|
|
I2 (%)
|
p value
|
p value
|
|---|
|
Cancer type
| | | | | | |
0.240
|
|
Breast cancer
|
4
|
1714
|
0.73 (0.23–2.27)
|
0.583
|
91.1
|
< 0.001
| |
|
Digestive system cancer
|
2
|
450
|
0.51 (0.25–1.03)
|
0.059
|
44.2
|
0.181
| |
|
Head and neck cancer
|
2
|
187
|
0.37 (0.15–0.92)
|
0.033
|
54.8
|
0.137
| |
|
Leukemia/lymphoma
|
2
|
188
|
0.39 (0.25–0.61)
|
< 0.001
|
0.0
|
0.921
| |
|
Others
|
1
|
320
|
0.28 (0.11–0.71)
|
0.007
|
–
|
–
| |
|
CD9 detection method
| | | | | | |
0.792
|
|
Flow cytometry
|
1
|
112
|
0.41 (0.17–0.95)
|
0.039
|
–
|
–
| |
|
IHC
|
9
|
2638
|
0.52 (0.30–0.90)
|
0.020
|
84.8
|
< 0.001
| |
|
RT-PCR
|
1
|
109
|
0.30 (0.14–0.63)
|
0.002
|
–
|
–
| |
|
Publication year
| | | | | | |
0.033
|
|
After 2005
|
5
|
1954
|
0.81 (0.41–1.62)
|
0.552
|
85.2
|
< 0.001
| |
|
Before 2005
|
6
|
905
|
0.33 (0.24–0.46)
|
< 0.001
|
0.0
|
0.456
| |
|
Race
| | | | | | |
0.354
|
|
Asian
|
7
|
2240
|
0.58 (0.30–1.12)
|
0.102
|
87.4
|
< 0.001
| |
|
Caucasian
|
4
|
619
|
0.40 (0.27–0.59)
|
< 0.001
|
0.0
|
0.402
| |
|
Sample size
| | | | | | |
0.896
|
|
Fewer than 140
|
5
|
444
|
0.46 (0.23–0.92)
|
0.028
|
69.5
|
0.011
| |
|
More than 140
|
6
|
2415
|
0.49 (0.26–0.94)
|
0.032
|
86.0
|
< 0.001
| |
- CI, confidence interval; HR, hazard ratio; IHC, immunohistochemistry; RT-PCR, reverse transcription-polymerase chain reaction
