Impact of absolute lymphocyte count on prognosis of aggressive non-Hodgkin lymphoma.

Abstract

e19034 Background: Multiple studies have attempted to identify parameters to predict prognosis and overall survival (OS) in Non-Hodgkin Lymphoma (NHL). Revised International Prognostic Index (R-IPI) is commonly used but does not capture all predictive risk factors in the Rituximab era. Low absolute lymphocyte count (ALC) on follow up after first line therapy has been reported to predict relapse. The prognostic value and exact cut off for low ALC at diagnosis is not known. We aimed to investigate whether ALC at time of diagnosis is an independent predictor for OS in aggressive NHL. Methods: We retrospectively evaluated patients with aggressive NHL treated at our center from 1/2000 to 12/2016 with at least 2 year longitudinal follow up after diagnosis. We retrieved data for baseline characteristics including age, sex, Ann Arbor stage, R-IPI score, HIV status, histopathological diagnosis (Diffuse Large B Cell Lymphoma (DLBCL), Burkitt′s lymphoma, Follicular Lymphoma Grade IIIB, high-grade B cell lymphoma), type of chemotherapy and clinical response. Patients were divided into four subgroups based on ALC at diagnosis: < 500, 501-1000, 1001-1500 and > 1500X109/L. Statistical analysis was done using REDCAP and Stata v13. Results: A total of 92 patients were identified. The average age at diagnosis was 53.4 years, 63% were male and 73.5% were diagnosed with DLBCL. Per R-IPI score, 16.3% were high risk, 31.3% were high intermediate risk, 22.5% low intermediate risk and 30% were low risk. The median OS for patients with ALC < 500 x109/L (5.4%) was 1.5 years, ALC 501-1000 (38%) was 2.3 years, ALC 1001-1500 (23.9%) was 4.25 years and ALC > 1500 (32.6%) was 5.2 years. On multivariate analysis this difference was not statistically significant due to small sample size. Conclusions: We found that low ALC at diagnosis trended towards worse OS in aggressive NHL but did not reach statistical significance on multivariate analysis. Our study is limited by retrospective nature and sample size. Multicenter studies need to be done to validate these results. Studies are also needed to know the exact cut off for low ALC. [Table: see text]