Table 2.
Basic characteristics and quality evaluation results of the included studies.
| Study | Year | Language | Hormonal receptor | Median age | Total | CSM Events |
|---|---|---|---|---|---|---|
| Kim et al. (10) | 2007 | English | No | 42 (25-68) | 50 | 20 |
| Loo et al. (11) | 2011 | English | Yes | - | 188 | 80 |
| Kim et al. (12) | 2012 | English | No | 46 (29-63) | 56 | 42 |
| Hu et al. (13) | 2012 | Chinese | No | 48.6 ± 7.2 | 35 | 15 |
| Mukhtar et al. (14) | 2013 | English | Yes | 48.5 (26.7–68.8) | 198 | 92 |
| Tomida et al. (15) | 2014 | English | No | - | 27 | 17 |
| Hu et al. (16) | 2014 | Chinese | No | – | 56 | 33 |
| Xiao (17) | 2014 | Chinese | No | 44.12 (35.55-52.69) | 44 | 24 |
| Zhou (18) | 2014 | Chinese | Yes | – | 54 | 24 |
| Bansal and Santosh (19) | 2016 | English | Yes | 47 (28-70) | 82 | 63 |
| Liao (20) | 2016 | Chinese | No | 48 | 35 | 28 |
| Ballesio et al. (21) | 2017 | English | Yes | No | 51 | 20 |
| Eom et al. (22) | 2017 | English | Yes | 45 ± 10.09 | 64 | 38 |
| Li et al. (23) | 2017 | English | Yes | 46 | 88 | 39 |
| Fukada et al. (24) | 2018 | English | Yes | – | 304 | 178 |
| Goorts et al. (25) | 2018 | English | No | 53 (29-72) | 57 | 25 |
| Shin et al. (26) | 2018 | English | No | 45.7 (22-75) | 391 | 168 |
| Zhang et al. (27) | 2018 | English | Yes | 52 (39.4-64.6) | 61 | 26 |
| Shao et al. (28) | 2018 | Chinese | Yes | 45 | 22 | 14 |
| Xu et al. (29) | 2018 | Chinese | Yes | - | 108 | 72 |
| Ling et al. (30) | 2019 | English | No | 55 (47-62) | 346 | 257 |
| Liu et al. (31) | 2019 | Chinese | No | 35-72 | 69 | 41 |
| Zhang et al. (32) | 2019 | Chinese | No | 48 | 48 | 39 |
Hormonal receptor “Yes”: The articles studied breast cancer hormonal receptor.
Hormonal receptor “No”: The articles did not study breast cancer hormonal receptor.