Features summary of the eligible studies in the meta-analysis.

Abbreviations: HR, hazard ratio; OS, overall survival; EFS, event-free survival; IHC, immunohistochemistry; FISH, interphase fluorescent in situ hybridization; RT-PCR, reverse transcription-polymerase chain reaction; qNPA, quantitative nuclease protection assay; LD-PCR, long-distance polymerase chain reaction; CHOP, cyclophosphamide, doxorubicin, vincristine, and prednisone; R-CHOP, rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone; CyclOBEAP, cyclophosphamide, vincristine, bleomycin, etoposide, doxorubicin, and prednisone; R-DHAP, rituximab, dexamethasone, aracytine, and cisplatin; R-ICE, rituximab, ifosfamide, etoposide, and carboplatin; NA, not available.