Table 3.
Subgroup analysis and meta-regression of the association between CD9 expression and disease-free survival in cancer patients
| 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