Table 1.
Characteristics of studies included in this meta-analysis of concentration of circulating cell-free DNA in the diagnosis of breast cancer.
| References | Country | No. of P/C | Study type | Sample | Time of sample collection | Test method | Reference gene | Cut of value | Sensitivity (%) | Specificity (%) |
|---|---|---|---|---|---|---|---|---|---|---|
| Leon et al. (22) | USA | 32/55 | Case-control | Serum | BS | Radioimmu-noassay | – | 50 ng/ml | 37.5 | 92.7 |
| Gal et al. (24) | UK | 96/24 | Case-control | Serum | BS | RT-qPCR | β-globin | – | 70.8 | 93.7 |
| Huang et al. (18) | China | 61/27 | Cohort | Plasma | BS | RT-qPCR | β-globin | 19 ng/ml | 95.1 | 88.9 |
| Catarino et al. (25) | Portugal | 175/80 | Cohort | Plasma | AS | RT-qPCR | hTERT | 106.0 ng/mL | 43.4 | 91.2 |
| Kohler et al. (19) | Switzerland | 52/70 | Cohort | Plasma | BS | RT-qPCR | GAPDH | 1866 GE/ml | 81.0 | 69.0 |
| Agostini et al. (13) | Italy | 39/49 | Case-control | Plasma | BS | RT-qPCR | ALU115 | 9.3394 ng/ml | 94.8 | 100.0 |
| Hashad et al. (20) | Egypt | 42/27 | Case-control | Plasma | BS | RT-qPCR | hTERT | 34 ng/ml | 97.6 | 96.3 |
| Gong et al. (21) | China | 200/100 | Cohort | Serum | BS | RT-qPCR | GAPDH | 471 ng/ml | 94.0 | 95.0 |
| Stötzer et al. (26) | Germany | 112/28 | Case-control | Plasma | BS | RT-qPCR | ALU115 | – | 95.0 | 57.1 |
| Agassi et al. (23) | Israel | 38/16 | Cohort | Serum | BS | Fluorescent SYBR Gold stain | – | 600 ng/mL | 72.0 | 75.0 |
| Tangvarasittichai et al. (27) | Thailand | 100/100 | Case-control | Plasma | BS | QubitTMflu-orometer | – | 120 ng/ml | 100.0 | 88.6 |
| Zhang et al. (28) | China | 100/104 | Case-control | Serum | BS | RT-qPCR | HOTAIR | Relative concent-ration 0.30 | 80.0 | 68.3 |
| Tang et al. (14) | China | 40/40 | Case-control | Serum | – | Fluorescence qPCR | ALU115 | 300.96 ng/mL | 65.0 | 70.0 |
P, patients; C, controls; BS, before surgery; AS, after surgery; RT-qPCR, real-time quantitative PCR.