Table 2.
Subgroup analyses of CD133 positivity in overall survival (OS).
| Factors | Subgroups | Studies | HR with 95% CI | Heterogeneity (P) | P value | Cases | TSA |
|---|---|---|---|---|---|---|---|
| Tumor type | Colorectal cancer | 6 | 1.27 (0.64-2.50) | < 0.001 | 0.493 | 848 | |
| Ovarian cancer | 2 | 3.27 (0.43-25.03) | 0.049 | 0.254 | 152 | ||
| Melanoma | 1 | 1.1 (0.34-3.8) | NA | > 0.05 | 32 | ||
| Cancer with bone metastases | 1 | 9.73 (1.08-87.49) | NA | < 0.05 | 50 | More | |
| Gastric cancer | 1 | 2.097 (1.003-4.383) | NA | < 0.05 | 100 | More | |
| Study source | Japanese | 4 | 0.90 (0.36-2.26) | 0.001 | 0.823 | 421 | |
| Chinese | 4 | 2.12 (1.35-3.33) | 0.154 | 0.001 | 579 | More | |
| Others | 3 | 2.07 (0.90-4.78) | 0.229 | 0.089 | 182 | ||
| Survival rate | 5 years | 3 | 1.26 (0.38-4.17) | 0.001 | 0.703 | 307 | |
| < 3 years | 2 | 10.92 (2.44-48.96) | 0.888 | 0.002 | 79 | More | |
| Others | 6 | 1.38 (0.85-2.26) | 0.01 | 0.197 | 796 | ||
| Sample type | Tissue | 9 | 1.51 (0.92-2.49) | < 0.001 | 0.103 | 1100 | |
| Blood | 2 | 2.68 (0.33-21.83) | 0.088 | 0.358 | 82 | ||
| Age (years) | > 60 | 2 | 2.09 (1.20-3.64) | 0.989 | 0.009 | 238 | More |
| ≤ 60 | 3 | 1.40 (0.31-6.27) | 0.01 | 0.661 | 149 | ||
| NA | 6 | 1.64 (0.92-2.91) | 0.003 | 0.093 | 795 | ||
| Treatment regimens | Adjuvant therapy | 4 | 1.91 (1.08-3.39) | 0.173 | 0.026 | 309 | More |
| Surgery and adjuvant therapy | 6 | 1.34 (0.62-2.93) | < 0.001 | 0.457 | 781 | ||
| Testing method | Blind | 3 | 1.64 (0.32-8.37) | < 0.001 | 0.553 | 455 | |
| NA | 8 | 1.62 (1.00-2.63) | 0.005 | 0.048 | 727 | More | |
| Study center design | Multicentre | 2 | 2.74 (0.46-16.19) | 0.097 | 0.266 | 173 | |
| Single-center | 8 | 1.54 (0.85-2.79) | < 0.001 | 0.154 | 977 | ||
| NA | 1 | 1.1 (0.34-3.8) | NA | > 0.05 | 32 | ||
| Sample size | ≥ 100 | 6 | 1.58 (0.97-2.57) | 0.007 | 0.066 | 891 | |
| < 100 | 5 | 1.93 (0.66-5.65) | 0.001 | 0.232 | 291 |
HR: hazard ratio; 95% CI: 95% confidence interval; NA: not applicable; TSA: trial sequential analysis.