Clinicopathological analysis of primary refractory diffuse large B‐cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy

Background Approximately 15% of patients with diffuse large B‐cell lymphoma (DLBCL) experience refractory or early relapsed disease after initial rituximab‐containing chemoimmunotherapy is regarded as a primary refractory disease. Although the standard treatment for relapsed DLBCL is high‐dose chemotherapy and autologous stem cell transplantation (HDC‐ASCT), the efficacy of this approach for primary refractory DLBCL is not well understood. We aimed to investigate the clinicopathological characteristics and outcomes of patients with primary refractory DLBCL. Methods Sixty‐nine consecutive patients with primary refractory DLBCL who were treated at our institution were categorized as partial responders (partial response to rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone [R‐CHOP] or relapse within 6 months of R‐CHOP) (n = 41) or primary progressors (no response to R‐CHOP) (n = 28). Survival curves were constructed using the Kaplan–Meier method and compared using the log‐rank test. Results At initial diagnosis, 70% of patients had Ann Arbor stage III/IV disease, 56% had non‐germinal center B‐cell‐like type DLBCL, and 42% had double‐expressor lymphoma (MYC and BCL2 expression). The 3‐year overall survival rate was significantly poorer in the primary progressors group than in the partial responders’ group (15% vs. 48%, p