Impact of cutoff age in predicting clinical outcomes of elderly diffuse large B cell lymphoma receiving rituximab or not: A hospital-based study

Background/PurposeElderly lymphomas are usually defined as disease onset at age more than 60 years according to the criteria of the International Prognostic Index (IPI). IPI, the standard risk stratification system of aggressive lymphoma, was proposed before the introduction of rituximab (a monoclonal antibody of CD20). While rituximab has markedly improved the outcomes of diffuse large B cell lymphomas (DLBCL), the appropriateness of IPI has been questioned. Meanwhile, applying modified IPI to patients at extreme age has also been suggested in some reports. Hence, this study aims to evaluate the impact of Elderly-IPI (E-IPI) with cutoff age at 70 years in elderly DLBCL receiving rituximab or not.MethodsIn a tertiary medical center, DLBCL patients older than 60 years were enrolled between January 2000 and December 2009. We excluded patients who did not receive first-line chemotherapy with CEOP/CNOP (cyclophosphamide, epirubicin/mitoxantrone, vincristine, and prednisone) plus rituximab or not. Patient characteristics and treatment outcomes were analyzed.ResultsIn total, 139 patients were included. Age cutoff 70 years was a significant impact factor in overall survival (OS) and progression-free survival (PFS) (p = 0.0044 and 0.0468). For the entire population, age more than 70 years was demonstrated to be an independent poor predictor in the multivariate analysis of OS (Hazard ratio: 3.441; 95% CI: 1.761–6.725; p < 0.001) and PFS (Hazard ratio: 1.934; 95% CI: 1.104–3.388; p = 0.021). In comparison with IPI (p = 0.0001 and 0.2126), E-IPI (p < 0.0001 and p = 0.0285) had significantly greater impact on OS and PFS. In the subgroup analysis, the statistical power of E-IPI and IPI influences were superior in the group receiving no rituximab versus the rituximab counterpart.ConclusionIn DLBCL with old age, age cutoff of 70 years demonstrated promising significance in survival and prognosis. In addition, E-IPI seemed more practical than IPI in the era of rituximab. Because of the limited numbers of patients analyzed in this retrospective study, further large-scale investigations are warranted to confirm these results.