Table 1. Baseline characteristics of included studies.
| First author | Year | Country | Patients | Tumor stage (ACJJ) | Methods | Target antigen/target gene | Cut off | Prognostic outcome |
|---|---|---|---|---|---|---|---|---|
| Winters [23] | 2015 | America | BC+UTUC | II–IV | CellSearch | EpCAM | - | - |
| Alva [24] | 2015 | America | BC | II–IV | IsoFlux | EpCAM | 10 CTCs/7.5 ml | - |
| Gazzaniga [29] | 2014 | Italy | BC | I | CellSearch | EpCAM | - | - |
| Lu [37] | 2000 | Japan | BC+UTUC | 0a–IV | Nested RT-PCR | UPII | - | - |
| Retz [18] | 2001 | Germany | BC | 0a–IV | RT-PCR | CK20 | - | - |
| Kinjo [34] | 2004 | Japan | BC | 0a–IV | Nested RT-PCR | MUC7 | - | - |
| Flaig [14] | 2011 | America | BC | 0a–IV | CellSearch | EpCAM | - | OS |
| Rink [42] | 2011 | Germany | BC | 0a–IV | CellSearch | EpCAM | 1 CTC/7.5 ml | OS/PFS/CSS |
| Li [36] | 1999 | America | BC | NR | RT-PCR | UPII | - | - |
| Naoe [15] | 2007 | Japan | BC+UTUC | 0a–IV | CellSearch | EpCAM | 2 CTCs/10 ml | - |
| Fujii [28] | 1999 | Japan | BC+UTUC | 0a–IV | Nested RT-PCR | CK20 | - | - |
| Gazzaniga [30] | 2001 | Italy | BC | 0a–IV | RT-PCR | EGFR/UPII/CK19/CK20 | - | - |
| Gudemann [33] | 2000 | Germany | BC+UTUC | 0a–IV | Nested RT-PCR | CK20 | - | - |
| Okegawa [39] | 2010 | Japan | BC+UTUC | I–IV | CellSearch | EpCAM | - | - |
| Antoniewicz [25] | 2012 | Poland | BC | ≥ 0a | RT-PCR | EGFR/COL1A1 | - | - |
| Ribal [17] | 2006 | Spain | BC | 0a–IV | Nested RT-PCR | CK20 | - | - |
| Rink [21] | 2012 | Germany | BC | 0a–IV | CellSearch | EpCAM | - | OS/PFS/CSS |
| Gradilone [20] | 2010 | Italy | BC | I | CELLection/RT-PCR | EpCAM/Survivin | - | DFS |
| Gazzaniga [31] | 2012 | Italy | BC | 0a–I | CellSearch | EpCAM | - | - |
| Soria [43] | 2002 | France | BC | 0a–IV | Telomerase assay | Telomerase activity | - | - |
| Guzzo [16] | 2012 | America | BC | 0a–IV | CellSearch | EpCAM | - | - |
| Okegawa [40] | 2004 | Japan | BC | 0a–IV | Nested RT-PCR | UPII/CK20 | - | DFS |
| Todenhofer [22] | 2016 | Germany | BC | 0a–IV | RT-PCR | HER2/MUC1/EpCAM/ALDH1 TWIST/AKT2/PI3Kα | - | - |
| Leotsakos [35] | 2014 | Greece | BC | 0a–IV | RT-PCR | EGFR/CK19/CK20 | - | - |
| Osman [41] | 2004 | America | BC | III–IV | Nested RT-PCR | UPIa/UPIb/UPII/UPIII/EGFR | - | - |
| Meye [38] | 2002 | Germany | BC | 0a–IV | ICC | CKs | - | - |
| Gazzaniga [32] | 2005 | Italy | BC | I–IV | RT-PCR | Tenascin C/EGFR | - | - |
| Desgrandchamps [27] | 1999 | UK | BC | 0a–IV | ICC | CK | - | - |
| Allard [19] | 2004 | America | BC | IV | CellSearch | EpCAM | - | - |
| Champelovier [26] | 1999 | France | BC | NR | Nested RT-PCR | CK20 | - | - |
BC: Bladder Cancer; UTUC: Upper Tract Urothelial Carcinoma; CTCs: Circulation Tumor Cells; RT-PCR: Quantitative Reverse Transcription Polymerase Chain Reaction; OS: Overall Survival; PFS: Progression-Free Survival; DFS: Disease-Free Survival; CSS: Cancer-Specific Survival.