R‐ CHOP versus dose‐adjusted R‐ EPOCH in frontline management of primary mediastinal B‐cell lymphoma: a multi‐centre analysis

Summary Primary mediastinal (thymic) large B‐cell lymphoma ( PMBCL ) is an uncommon subtype of non‐Hodgkin lymphoma ( NHL ) that presents with a mediastinal mass and has unique clinicopathological features. Historically, patients with PMBCL were treated with R‐ CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy ± involved field radiation. Since a phase II trial, published in April 2013, demonstrated excellent results using dose‐adjusted ( DA ) R‐ EPOCH (rituximab, etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin), this treatment has gained popularity. We performed a retrospective, multicentre analysis of patients aged ≥18 years with PMBCL since January 2011. Patients were stratified by frontline regimen, R‐ CHOP versus DA ‐R‐ EPOCH . 132 patients were identified from 11 contributing centres (56 R‐ CHOP and 76 DA ‐R‐ EPOCH ). The primary outcome was overall survival. Secondary outcomes included progression‐free survival, complete response ( CR ) rate, and rates of treatment‐related complications. Demographic characteristics were similar in both groups. DA ‐R‐ EPOCH use increased after April 2013 (79% vs. 45%, P < 0·001), and there was less radiation use after DA ‐R‐ EPOCH (13% vs. 59%, P < 0·001). While CR rates were higher with DA ‐R‐ EPOCH (84% vs. 70%, P = 0·046), these patients were more likely to experience treatment‐related toxicities. At 2 years, 89% of R‐ CHOP patients and 91% of DA ‐R‐ EPOCH patients were alive. To our knowledge, this represents the largest series comparing outcomes of R‐ CHOP to DA ‐R‐ EPOCH for PMBCL .