Table 1.
Characteristics of each study
| First author | Year | Country | Cancer types | Sample size | Cut off | Median age | Median follow-up (month) | Research type | Survival analysis | HR type | NOS |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mahmoud | 2012 | UK | Primary invasive BC | 1214 | 1 cell | 55 | 250 | Retrospective analysis | BCSS | Reported | 6 |
| Garaud 1 | 2019 | Belgium | HER2 + BC | 136 | 0.055 | NR | 120 | Retrospective analysis | OS, DFS | Reported | 8 |
| Garaud 2 | 2019 | Belgium | TNBC | 113 | 0.0275 | NR | 120 | Retrospective analysis | OS, DFS | Reported | 8 |
| Arias-Pulido | 2018 | Algeria | IBC | 221 | 0.01 | NR | 96 | Retrospective analysis | OS, DFS | Estimated | 5 |
| Yeong | 2018 | Singapore | TNBC | 269 | 0.05 | 55 | 97 | Retrospective analysis | OS, DFS | Reported | 7 |
| Xu | 2018 | China | Invasive ductal BC | 102 | 115 cells | 48 | 60 | Retrospective analysis | OS, DFS | Reported | 6 |
| Mohammed | 2013 | UK | Primary operable ductal invasive BC | 338 | 5 cells | NR | 164 | Retrospective analysis | BCSS | Reported | 8 |
| Boissière-Michot | 2020 | France | TNBC | 105 | NR | NR | 120 | Retrospective analysis | RFS | Reported | 7 |
| Yu | 2013 | China | BC | 130 | NR | NR | NR | Retrospective analysis | OS, DFS | Estimated | 6 |
BC breast cancer; TNBC triple-negative breast cancer; IBC inflammatory breast cancer; HER2 human epidermal growth factor receptor-2; NR not reported; BCSS breast cancer-specific survival; OS overall survival; DFS disease-free survival; RFS relapse-free survival; HR hazard ratio; NOS Newcastle-Ottawa Quality Assessment Scale