PB2135: BURKITT LYMPHOMA INTERNATIONAL PROGNOSTIC INDEX (BL-IPI): IS IT EFFICIENT ENOUGH IN ADULT BURKITT LYMPHOMA PATIENTS?

Abstract

Background: Burkitt lymphoma is a rare but clinically severe subtype of non-Hodgkin lymphoma. An ideal risk scoring system specific to Burkitt lymphoma had not been available for many years, however Burkitt Lymphoma International Prognostic Index (BL-IPI) has been recently proposed by Olszewski et al. BL-IPI is consisted of following risk factors; age ≥ 40 years, performance status ≥ 2, serum lactate dehydrogenase (LDH) ≥ 3X upper limit of normal (ULN), and central nervous system (CNS) involvement. Accordingly, patients are grouped as low risk (zero risk factor) disease, intermediate risk (one risk factor) and high risk (≥2 risk factors). Aims: Our aims were to examine the basic characteristics and survival rates of Burkitt lymphoma patients that are being treated in our institution, to determine the prognostic factors which affect survival and to evaluate the efficacy of BL-IPI and other risk scoring systems in our patient population. Methods: Patients who were 18 years or older and diagnosed with Burkitt lymphoma between 2000-2021 at Hacettepe University Hospital were included in our study. Patient, disease and treatment characteristics were reviewed through hospital electronic health records. Disease free survival (DFS) and overall survival (OS) were determined as the primary endpoints. Variables that have prognostic impact were identified through univariate and multivariate analyses. Finally, the efficacy of BL-IPI was tested in our patient population. Statistical analyses were conducted using SPSS version 25. Results: A total of 71 patients whose median age of diagnosis was 40 (IQR: 29-55) and median follow-up time was 11,4 months (minimum 0,33, maximum 243,67 months) were included in our study. 1 year OS was estimated as 58%, 3 year OS as 53% and 3 year DFS as 64%. Factors affecting survival were examined and in univariate analyses; performance status ≥ 2, stage 4 disease, bone marrow involvement, CNS involvement, serum LDH > ULN, hypoalbuminemia, anemia and thrombocytopenia were associated with lower 3-year OS (p<0,05); while stage 4 disease, bone marrow involvement, anemia and thrombocytopenia were associated with lower 3-year DFS (p<0,05). In multivariate analysis, only performance status ≥ 2, stage 4 disease, bone marrow involvement and thrombocytopenia caused a statististically significant increase in death rate (p<0,05). CNS involvement caused a near significant increase (p=0,067). 25,4% of the patients had low risk, 31% of the patients had intermediate risk and 34,6% of the patients had high risk disease according to BL-IPI. 3-year OS rates were 82%, 65% and 27% respectively, and 3-year PFS rates were 81%, 71% and 36% respectively. Image:Summary/Conclusion: Our study supports the fact that BL-IPI predicts survival efficiently, however taking our aforementioned results into consideration, we propose that instead of “CNS involvement”, “CNS involvement and bone marrow involvement” or “stage 4 disease” could be added to the score as a risk factor. In the study conducted by Olszewski et al., 58% of the patients in the low risk group had advanced stage disease, however only 12% had bone marrow involvement, which is a relatively low ratio compared to literature. Studies involving larger cohorts who have higher bone marrow involvement ratios consistent with the literature are undoubtedly needed to support this proposition.