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, beta2microglobulin level, presence of B symptoms or bulky disease, and ALC were evaluated.

Results: Low ALC (<1.0 x 10(9)/L) was associated with advanced stage, performance status >or=2, elevated lactate dehydrogenase, number of extranodal involvement >or=2, B symptoms, elevated beta2microglobulin 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.