International Prognostic Index for Risk Stratification of DLBCL patients
The International Prognostic Index (IPI) and its revised variant, R-IPI are widely used clinical prognostication systems for DLBCL (15,16). These indices use a combination of age, Eastern Cooperative Oncology Group (ECOG) performance status, tumor stage, lactate dehydrogenase level, and the number of extra nodal sites of disease to predict the prognosis of patients with DLBCL (17). Biccler et al showed the poor performance of the IPI in predicting overall survival in DLBCL patients. (18) In a study investigating the ability of the IPI and the revised index to predict outcome, R-IPI identified three distinct prognostic groups with: (a) very good (4-year progression-free survival [PFS] 94%, overall survival [OS] 94%), (b) good (4-year PFS 80%, OS 79%), and (c) poor (4-year PFS 53%, OS 55%) outcomes, respectively (P< 0.001) (19). However, neither the R-IPI nor IPI are unable to predict patients with <50% chance of survival. Such patients potentially need more potent first lines of therapy. However, there are no biomarkers that can reliably identify these high risk patients as of yet.