Table 1.
Characteristics of included studies
| Author (year) | Design | No. of patients | Age (year) | Detection method | Endpoint | Source of HR | Adjusted covariates | Follow-up |
|---|---|---|---|---|---|---|---|---|
| Knechtli et al. (1998) | Retrospective | 64 | 1.3–17 | PCR IG/TCR | 2-year EFS | Multivariate analysis | Philadelphia chromosome positive, pre-BMT relapse | Median: 35 months |
| Bader et al. (2002) | Retrospective | 41 | 1.5–17.8 | PCR IG/TCR | 5-year EFS | KM curve | NA | Median: 5.75 years |
| Sramkova et al. (2007) | Prospective | 36 | 1.1–19 | PCR IG/TCR | 4-year EFS | KM curve | NA | Median: 26 months |
| Spinelli et al. (2007) | Prospective | 37 | 18–63 | PCR IG/TCR, or PCR fusion transcript | 3-year CIR, 3-year OS | KM curve | NA | Median: 23 months |
| Bader et al. (2009) | Prospective | 91 | 3–22.6 | PCR IG/TCR | 4-year CIR; 4-year EFS | Multivariate analysis | Sex, age at relapse, remission status, time point of relapse, immunophenotype, site of relapse, stem-cell donor, T-cell depletion, time to transplantation, GVHD, MRD load before stem-cell transplantation | Median: 3.4 years |
| Elorza et al. (2010) | Prospective | 31 | 0.8–12 | FC | 2-year EFS | KM curve | NA | Median: 9 months |
| Lankester et al. (2010) | Prospective | 48 | Mean: 8 | PCR IG/TCR | 5-year CIR, 5-year EFS | KM curve | NA | Median 61.5 months |
| Doney et al. (2011) | Retrospective | 161 | 18–62 | FC | 5-year CIR, 5-year RFS | Multivariate analysis | Disease status, year of transplantation, CMV serology mismatch | NA |
| Bachanova et al. (2012) | Prospective | 86 | 1–63 | FC | 2-year CIR, 3-year DFS, 3-year OS | Multivariate analysis | Disease status, ALL subtype, sex, time from diagnosis to transplantation, CMV status | Median 3.9 years |
| Ruggeri et al. (2012) | Retrospective | 170 | < 1–17 | PCR IG/TCR, or fusion transcripts | 4-year CIR; 4-year LFS, 4-year OS, 4-year NRM | Multivariate analysis | Age, median year of transplant, cytogenetic risk group, TBI-based conditioning regimen, number of HLA disparities | Median: 48 months |
| Mizuta et al. (2012) | Prospective | 100 | 15–64 | PCR BCR-ABL | 3-year CIR, 3-year OS, 3-year DFS, 3-year NRM | Multivariate analysis | Age, donor status, chromosome abnormality, stem-cell source, performance status, BCR-ABL subtype, WBC, CD20 | Median: 31 months |
| Sanchez-Garcia et al. (2013) | Retrospective | 102 | Mixed | FC | 5-year EFS, 5-year OS, 5-year RFS | Multivariate analysis | Age, disease status, stem-cell source, time from onset to HSCT, GVHD | Median: 60.8 months |
| Balduzzi et al. (2014) | Prospective | 82 | < 1–20 | PCR IG/TCR | 5-year CIR, 5-year EFS | Multivariate analysis | Disease status, donor type, HLA compatibility, GVHD | Median 4.9 years |
| Gandemer et al. (2014) | Prospective | 122 | ≤18 | PCR IG/TCR | 5-year CIR, DFS, OS | Multivariate analysis | Sex, antithymocyte globulins, CNS location, risk stratification | Median: 34.8 months |
| Tucunduva et al. (2014) | Retrospective | 98 | 18–66 | PCR or FC BCR-ABL | 3-year CIR, 3-year LFS | Multivariate analysis | Age, sex, cytomegalovirus, disease status, transplantation method, conditioning, antithymocyte globulin, use of TKI, graft | Median: 36 months |
| Logan et al. (2014) | Retrospective | 29 | 16–67 | PCR | DFS | KM curve | NA | Minimum: 3 years |
| Zhou et al. (2014) | Retrospective | 149 | 18–70 | FC | 2-year OS, 2-year PFS | Multivariate analysis | Age, disease status, allotype, cell type | NA |
| Bar et al. (2014) | Retrospective | 160 | 0.6–62 | FC | 3-year CIR, 3-year OS | Univariate analysis | None | Median: 40.6 months |
| Bader et al. (2015) | Prospective | 113 | 0–18 | PCR IG/TCR | 3-year CIR, 3-year EFS, 3-year NRM | Multivariate analysis | Disease status, immunophenotype, time of relapse, T-cell depletion | Range: 3.4–6.5 years |
| Sutton et al. (2015) | Prospective | 81 | < 18 | PCR IG/TCR | 5-year CIR, 5-year LFS, 5-year OS | Multivariate analysis | Sex, age, T-ALL, BCR-ABL1, hyperdiploidy > 50 or ETV6-RUNX1, BCP-other, IKZF1 mutation status, CR > 1, MSD, cord blood donor, mitoxantrone chemotherapy, TBI CY TT conditioning, in vitro T-cell depletion, ATG, GVHD | Median: 4.8 years |
| Dh’edin et al. (2016) | Prospective | 522 | 15–55 | PCR IG/TCR | 3-year RFS, 3-year OS | KM curve | NA | Median: 3.5 years |
ALL Acute lymphoblastic leukemia, BMT Bone marrow transplantation, CIR Cumulative incidence of relapse, CNS Central nervous system, DFS Disease-free survival, EFS Event-free survival, FC Flow cytometry, GVHD Graft-versus-host disease, HR hazard ratio, IG Immunoglobulin genes, MRD Minimal residual disease, MSD Matched sibling donor, NRM non-relapse mortality, OS Overall survival, RFS Relapse-free survival, TBI total body irradiation, TCR T-cell receptor genes, TKI Tyrosine-kinase inhibitor