Table 1.
Summary of studies included in the meta-analysis
| Author | Year | Sample | Country | Duration | Age (years) | Follow-up (months) | Subtype | Stage | Cut-off value | Method for cut-off | Outcomes | Hr (M/U) | NOS score |
| Koh17 | 2014 | 157 | Korea | 2002–2010 | 44 (24–71) | 21 (1–108) | HR+/HER2− | II-IV | 2.25 | ROC | PCR/RFS/OS | M/U | 6 |
| Asano18 | 2016 | 61 | Japan | 2007–2013 | 56 | 40.8 (7.2–72) | TNBC | II-III | 3 | Ref | PCR/DFS/OS | M/U | 6 |
| Chen19 | 2016 | 215 | China | 2001–2010 | 44.61±9.82 | 55 (36.1–75.8) | All | II-III | 2.1 | ROC | PCR/RFS/BCSS | M/U | 7 |
| Marin Hernandez20 | 2018 | 150 | Spain | 2013–2016 | 49.8 (28–77) | 24 (1–144) | All | II-III | 3.33 | ROC | PCR/DFS/OS | NR | 7 |
| Chae21 | 2018 | 87 | Korea | 2004–2012 | 45.8±11.2 | 57 | TNBC | I-III | 1.7 | ROC | PCR/RFS | M | 7 |
| Geng22 | 2018 | 96 | China | 2002–2014 | 53.6±10.6 | 24 | All | I-III | 1.878 | ROC | DFS | U | 6 |
| Goto23 | 2018 | 239 | Japan | 2007–2015 | 55 | 44.4 (2.4–72) | All | II-III | 1.63 | ROC | PCR/DFS/OS | U | 7 |
| Li24 | 2018 | 310 | China | 2006–2013 | 43.9±12.0 | 62.5 (9.6–138.5) | HER2-positive | I-III | 2.7 | ROC | DFS/OS | M/U | 7 |
| Qian25 | 2018 | 180 | China | 2008–2015 | 46 (23–71) | 22.7 (3–85) | All | II-III | 2.15 | Median | PCR /DFS | NR | 6 |
| Losada26 | 2018 | 104 | Spain | 2004–2018 | 71 (65–89) | 48 (6–149) | All | I-III | 3.33 | Ref | PCR/DFS/OS | NR | 6 |
| Lee27 | 2019 | 50 | Korea | 2008–2015 | 43.5 (25–66) | NR | TNBC | II-III | 3.16 | ROC | PCR | NR | 6 |
| Graziano28 | 2019 | 373 | Italy | 1999–2018 | 50 (26–82) | NR | All | II-III | 2.42 | ROC | PCR | NR | 6 |
| Dan29 | 2020 | 242 | China | 2012–2017 | 50 (32–70） | NR | All | II-III | 3.1 | Mean | PCR | NR | 6 |
| Muñoz-Montaño30 | 2020 | 1519 | Mexico | 2007–2015 | 49 (22–88) | 52.9 (6–121) | All | I-III | 2 | ROC | PCR/DFS/OS | M/U | 8 |
| Bae31 | 2020 | 1097 (638/459) | Korea | 2007–2018 | 47 (20–84） | 56 (5–152) | (HR+/HER2−(638) and TNBC (459)) | I-III | 2.74 | ROC | PCR/DFS/OS | M/U | 8 |
| Eren32 | 2020 | 131 | Turkey | 2009–2018 | 49 (23–74） | NR | All | II-III | 1.95 | ROC | PCR | NR | 6 |
| Hu33 | 2020 | 480 | China | 2012–2016 | 40 | NR | HR+/HER2− | I-III | NR | NR | PCR | NR | 6 |
| Dong34 | 2020 | 170 | China | 2010–2014 | NR | 34 (6–74) | TNBC | II-III | 1.928 | Median | PCR/DFS | M | 7 |
| Jiang35 | 2020 | 249 | China | 2014–2018 | 51 | 31 (4–72) | All | I-III | 2.13 | ROC | PCR/OS | M/U | 8 |
‘M’ means the HR come from multivariate analysis, ‘U’ means the HR comes from univariate analysis, M/U means both were available in the original study.
BCSS, breast cancer-specific survival; DFS, disease-free survival; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; NOS, Newcastle-Ottawa Quality Assessment Scale; NR, not reported; OS, overall survival; pCR, pathological complete response; ref, reference; RFS, Recurrence-free survival; ROC, receiver operating characteristic; TNBC, triple negative breast cancer.