A clinically based prognostic index for diffuse large B-cell lymphoma with a cut-off at 70 years of age significantly improves prognostic stratification: Population-based analysis from the Danish Lymphoma Registry

The introduction of rituximaband generally improved health among elderly patients have increased the survival of patients with diffuse large B-cell lymphoma(DLBCL). The International Prognostic Index(IPI) from 1992 is based on pre- rituximabdata from clinical trials including several lymphoma subtypes. We applied IPI factors to a population-based rituximab-treated cohort of 1990 patients diagnosed 2000–2010 and explored new factors and the optimal prognosticage cut-off for DLBCL. Multivariate-analyses (MVA) confirmed the prognosticvalue of all IPI factors except the presence of > 1 extranodal lesion. The optimal age cut-off was 70 years. In a MVA of albumin, lymphocyte count, sex, immunoglobulin G, bulky disease, hemoglobin and B-symptoms, only albumin was prognostic. We propose: (1) a modified DLBCL prognosticindex (DLBCL-PI) including: age (70 years), performance status(PS), lactate dehydrogenase (LDH), stage and albumin level, and (2) a separate age-adjustedDLBCL-PI for patients ≤ 70 years incl...