Validation of the International Prognostic Index and Subsequent Revisions for Diffuse Large B-Cell Lymphoma in Patients From the Middle East and North Africa Region

Diffuse large B-cell lymphoma (DLBCL) is a heterogenous disease with a variable prognosis. The International Prognostic Index (IPI), revised-IPI (R-IPI), and National Comprehensive Cancer Network-IPI (NCCN-IPI) have been developed and validated to predict prognosis in DLBCL. However, patients from the Middle East and North Africa (MENA) region were under-represented in such scores, and it is unclear whether ethnic background contributes to different disease biology or response to therapy. Following due Institutional Board Review approval, DLBCL patients diagnosed from January 2010 until December 2015 from the MENA region were retrospectively reviewed. A total of 122 were identified and further analyzed. There were 74 males (61%), and the median age at diagnosis for the cohort was 64 years (range: 18-98 years), with a median follow-up duration of 32.9 months (range: 0.2-123.7 months). Estimates of three-year progression-free survival found a significant difference among risk groups using all three prognostic models but were more discriminating among the groups using NCCN-IPI and R-IPI vs. IPI (p = 0.019 and 0.014 vs. 0.039, respectively). For overall survival estimates at three years, the NCCN-IPI was the best model compared to R-IPI and IPI (p = 0.0013 vs. 0.05 and 0.04, respectively). In conclusion, we validated that the IPI and its subsequent iterations were predictive of outcome in DLBCL patients from the MENA region; however, the NCCN-IPI appeared the most prognostic. These results warrant further confirmation.