Low absolute lymphocyte count is a poor prognostic marker in patients with diffuse large B-cell lymphoma and suggests patients' survival benefit from rituximab

Objectives: To evaluate the prognostic value of absolute lymphocyte count (ALC) at diagnosis in patients with diffuse large B‐cell lymphoma (DLBCL). Methods: In a large cohort of patients with DLBCL treated with CHOP (n = 119) or RCHOP (n = 102) in our institution, we evaluated the prognostic value of ALC at diagnosis with regards to treatment response, overall (OS) and progression‐free survival (PFS). Use of rituximab, all International Prognostic Index (IPI) determinants, β2microglobulin level, presence of B symptoms or bulky disease, and ALC were evaluated. Results: Low ALC (<1.0 × 10⁹/L) was associated with advanced stage, performance status ≥2, elevated lactate dehydrogenase, number of extranodal involvement ≥2, B symptoms, elevated β2microglobulin and higher IPI risk group. Low ALC was associated with lower CR rate by univariate analysis (odds ratio = 3.29, P = 0.024) but not by multivariate analysis. By univariate analysis using Cox proportional hazard model, low ALC was associated with shorter OS [hazard ratio (HR) = 2.89, P < 0.001] and PFS (HR = 2.91, P < 0.001). Multivariate analysis revealed that low ALC was associated with shorter OS (HR = 2.51, P = 0.003) and PFS (HR = 2.72, P < 0.001), independent of above‐mentioned parameters. Subclass analyses revealed that the use of rituximab improves OS in patients with low ALC (HR = 0.42, P = 0.05) but not in those with high ALC (HR = 0.83, P = 0.71). This observation was most obvious in patients with higher IPI score. Conclusion: Low ALC is a poor prognostic marker in patients with DLBCL and suggests patients’ survival benefit from rituximab.