Do We Have the Right Prognostic Index for Diffuse Large B Cell Lymphoma (DLBCL) in the Era of Rituximab?

Introduction: Whilst the addition of rituximab, a humanized monoclonal antibody to standard CHOP chemotherapy (R-CHOP) has improved the outcomes of DLBCL, the validity of the previously identified prognostic index based on clinical parameters is questioned. It is conceivable that prognostic model may alter with introduction of new therapeutics with differing efficacy and mechanisms of action. Methods: We conducted a retrospective analysis comparing the relevance of International Prognostic Index (IPI), Age-adjusted IPI and Revised International Prognostic Index (R-IPI) in 320 consecutive patients with DLBCL from 2003–2008 treated with R-CHOP chemotherapy with curative intent. We evaluated the prognostic factors determinant of survival in our group of patients. Results: Patients were followed up for a median of 2.70 years. IPI was only able to stratify patients into 3 main risk groups instead of 4. In addition, among patients <60, aa-IPI no longer seem a robust prognostic model. We showed that R-IPI was able to separate patients into 3 different prognostic groups and perhaps most relevant in the era of chemo-immunotherapy. Significant prognostic factors identified in multivariate analysis were performance status (P=0.004) and bone marrow involvement (P=0.026). Conclusion: The most robust prognostic index for patients with DLBCL in the era of rituximab remains uncertain. Incorporation of molecular markers into clinical parameters should be evaluated, a study we are embarking on.