|
Subgroup
|
Number of studies
|
Number of patients
|
Pooled HR (95% CI)
|
p value
|
Heterogeneity
|
Meta-regression
|
|---|
|
I2 (%)
|
p value
|
p value
|
|---|
|
Cancer type
| | | | | | |
0.298
|
|
Breast cancer
|
2
|
252
|
0.27 (0.12–0.63)
|
0.002
|
0.0
|
0.761
| |
|
Digestive system cancer
|
4
|
410
|
0.39 (0.24–0.63)
|
< 0.001
|
6.6
|
0.360
| |
|
Head and neck cancer
|
1
|
34
|
0.45 (0.20–1.01)
|
0.052
|
-
|
-
| |
|
Leukemia/lymphoma
|
2
|
224
|
1.17 (0.33–4.09)
|
0.809
|
85.7
|
0.008
| |
|
Others
|
2
|
221
|
0.39 (0.24–0.65)
|
< 0.001
|
15.8
|
0.276
| |
|
CD9 detection method
| | | | | | |
0.015
|
|
Flow cytometry
|
2
|
224
|
1.17 (0.33–4.09)
|
0.809
|
85.7
|
0.008
| |
|
IHC
|
6
|
659
|
0.42 (0.30–0.60)
|
< 0.001
|
0.0
|
0.532
| |
|
RT-PCR
|
3
|
258
|
0.30 (0.18–0.50)
|
< 0.001
|
0.0
|
0.993
| |
|
Publication year
| | | | | | |
0.060
|
|
After 2005
|
4
|
444
|
0.74 (0.36–1.53)
|
0.417
|
79.6
|
0.002
| |
|
Before 2005
|
7
|
697
|
0.33 (0.23–0.48)
|
< 0.001
|
0.0
|
0.708
| |
|
Race
| | | | | | |
0.804
|
|
Asian
|
9
|
995
|
0.45 (0.26–0.78)
|
0.004
|
71.7
|
< 0.001
| |
|
Caucasian
|
2
|
146
|
0.54 (0.32–0.91)
|
0.020
|
0.0
|
0.567
| |
|
Sample size
| | | | | | |
0.257
|
|
Fewer than 110
|
5
|
400
|
0.37 (0.26–0.53)
|
< 0.001
|
0.0
|
0.875
| |
|
More than 110
|
6
|
741
|
0.57 (0.28–1.18)
|
0.131
|
76.5
|
0.001
| |
- CI confidence interval, HR hazard ratio, IHC immunohistochemistry, RT-PCR reverse transcription-polymerase chain reaction
