Table 2.
Up-to-date meta-analyses of RCTs for 9 cancer outcomes and classification of evidence credibility.
| Outcomes | Number of Studies | Number of Trials | Events | Sample Size | Estimates (95% CI) | P | I2 (%) | 95% PI | PEgger | P Excess | Class |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Cancer Incidence | |||||||||||
| CRC | 4 | 7 | 902 | 81,119 | 0.74 (0.56-0.97) | 0.031 | 73 | 0.43-1.27 | 0.248 | 0.154 | IV |
| Gastric cancer | 1 | 2 (IPD) | 46 | 6,076 | 1.01 (0.54-1.86) | 0.990 | - | - | - | - | NS |
| Breast cancer | 1 | 2 (IPD) | 12 | 6,076 | 0.90 (0.26-3.07) | 0.860 | - | - | - | - | NS |
| Prostate cancer | 1 | 2 (IPD) | 313 | 6,076 | 0.87 (0.69-1.10) | 0.250 | - | - | - | - | NS |
| Lung cancer | 4 | 5 | 756 | 73,222 | 0.98 (0.84-1.13) | 0.757 | 0 | 0.84-1.13 | 0.179 | 0.220 | NS |
| Cancer-specific Mortality | |||||||||||
| CRC | 2 | 5 | 292 | 19,172 | 0.63 (0.49-0.80) | 2.01E-04 | 2 | 0.49-0.81 | 0.312 | 0.307 | IV |
| Gastric cancer | 1 | 3 (IPD) | 71 | 10,502 | 0.69 (0.43-1.10) | 0.110 | - | - | - | - | NS |
| Prostate cancer | 1 | 3 (IPD) | 210 | 10,502 | 0.81 (0.61-1.06) | 0.120 | - | - | - | - | NS |
| Lung cancer | 1 | 3 (IPD) | 326 | 10,502 | 0.71 (0.58-0.89) | 0.002 | - | - | - | - | IV |
Number of studies represents the total number of studies included in the meta-analysis for the specific cancer. Number of trials is the total number of clinical trials included in the meta-analysis. The inconsistency between these two numbers is due to that some studies used individual patient data from multiple trials for analysis. CRC, colorectal cancer; IPD, individual patient data; PI, prediction interval; NS, not significant.