R-CHOP14 As a Standard of Care in Primary Mediastinal B Cell Lymphoma: A 10-YEARS Experience of Lysa Centers

Introduction: Primary mediastinal B cell lymphoma (PMBL) is clinically and biologically distinct from the other subtypes of diffuse large B cell lymphoma (DLBCL), typically affecting young female patients (pts) with a bulky mediastinal mass. Standard treatment (TRT) is a combination of anti-CD20 antibody (Ab) and anthracycline-based chemotherapy. We aimed to compare patients' outcomes after CHOP delivered every 21 days (CHOP21) or 14 days (CHOP14) or ACVBP combined with anti-CD20 Ab in real life. Methods: All Pts treated in LYSA centers were eligible in this retrospective analysis. Inclusion criteria were as follow: age ≥18 years (yrs), newly diagnosed PMBL, TRT with CHOP or ACVBP plus anti-CD20 Ab between 2006 and 2017, and patient non-opposition statement. Primary endpoint was progression-free survival (PFS), secondary endpoints were: overall survival (OS), response rate (Lugano 2014) and total metabolic tumor volume (TMTV). Results: 313 pts were enrolled from 25 LYSA centers in France and Belgium. In all, median age at diagnosis was 32 (18-88) yrs. Majority of pts were female pts (60.7%) and presented at diagnosis with a good performance status (0-1: 81.8%), stage I-II (57.5%), elevated LDH (85%), Bulk>10cm (58.5%) and low/low-intermediate aaIPI 0-1 (56.7%). Pts in the CHOP21 (n=57) group were older (median 40 yrs, vs 33 vs 29.5, p