Day 15 peripheral blood lymphocyte/monocyte ratio post-autologous peripheral hematopoietic stem cell transplantation and survival in diffuse large B-cell lymphoma.

Abstract

8018 Background: Day 15 absolute lymphocyte count (ALC-15) post-autologous peripheral hematopoietic stem cell transplantation (APHSCT) is a prognostic factor for survival. Monocyte-derived cells affect tumor growth by suppression of host anti-tumor immunity and promotion of tumor angiogenesis (tumor microenvironment). Thus, we set out to investigate if the absolute lymphocyte count/absolute monocyte count ratio at day 15 (ALC/AMC-15 ratio), as a simple biomarker of host immunity and tumor microenvironment, affects survival post-APHSCT. Methods: From 1994 to 2007, 256 consecutive diffuse large B-cell lymphoma (DLBCL) patients that underwent APHSCT were studied. Results: The median follow-up for the cohort was 2.8 years (range: 0.1-17 years). Patients with an ALC/AMC-15 ratio ≥1 experienced a superior overall survival (OS) compared with patients with an ALC/AMC-15 < 1 post-APHSCT (median OS was not reached vs 9.9 months, 5-year OS rates of 86% vs 16%, p < 0.0001, respectively). Progression-free survival (PFS) was also superior if the ALC/AMC-15 ratio was ≥ 1 vs < 1 (median PFS was 197 months vs 4.4 months, 5-year PFS rates of 83% vs 10%, p < 0.0001, respectively). Multivariate analysis showed ALC/AMC-15 ratio to be an independent prognostic factor for OS and PFS post-APHSCT. Conclusions: ALC/AMC-15 ratio is associated with clinical outcomes post-APHSCT in DLBCL patients and warrants further studies.