Rituximab in combination with CHOP chemotherapy for the treatment of diffuse large B cell lymphoma in China: a 10-year retrospective follow-up analysis of 437 cases from Shanghai Lymphoma Research Group

The purpose of the study is to evaluate the 10 years follow-up of the efficacy in Chinese patients receiving cyclophosphamide, doxorubicin/epirubicin, vincristine, and prednisone (CHOP) or rituximab plus CHOP (R-CHOP) regimen as the initial treatment for diffuse large B cell lymphoma (DLBCL). We have retrospectively analyzed 437 patients with DLBCL who were newly diagnosed and received CHOP or R-CHOP regimen in six university hospitals and closely followed up after the completion of treatment. For all patients, there were significant differences between R-CHOP and CHOP for overall survival (OS) (median follow-up 86 months, 84.1% vs 70.2%, p = 0.018) and progression-free survival (PFS) (81.5% vs 66.7%, p = 0.015), while elder patients (>60 years old) received higher OS (median follow-up 66 months, 80.7% vs 53.0%, p = 0.011). But for younger patients (≤60 years old), the treatments with rituximab did not demonstrate a significant effect on OS (85.5% vs 79.4%, p = 0.428). In the R-CHOP group, International Prognostic Index (IPI) distinguished three risk groups instead of four risk groups. But in the CHOP group, IPI still distinguished four risk groups. Furthermore, for 212 of 437 patients diagnosed with extranodal involvement DLBCL, R-CHOP regimen provided a longer OS than CHOP regimen did (OS, 89.9% vs 71.7%, p = 0.014). Moreover, patients with extranodal lymphoma had a significant longer survival in rituximab era (OS, 89.9% vs 79.2% for extranodal and nodal, respectively; p = 0.048). The results of this large-scale study suggested that R-CHOP provided a greater survival benefit in the initial treatment of DLBCL. As for the patients with extranodal lymphoma, R-CHOP was also a good choice as first-line treatment. Extranodal disease seems to be an independent good prognostic factor in rituximab era.