Low lymphocyte-to-monocyte ratio predicts poor outcome in high-risk aggressive large B-cell lymphoma

Low lymphocyte-to-monocyte-ratio (LMR) has been associated with unfavorable survival in patients with diffuse large B-cell lymphoma (DLBCL). To date, however, the impact of LMR on survival has not been examined in a uniformly treated cohort of patients with high-risk aggressive large B-cell lymphoma. We collected peripheral blood absolute lymphocyte counts (ALCs) and absolute monocyte counts (AMC) prior to treatment and calculated LMR from 112 adult patients, who were less than 65 years of age, had age-adjusted International Prognostic Index 2-3, or site-specific risk factors for central nervous system (CNS) recurrence, and were treated in a Nordic Lymphoma Group LBC-05 trial with dose-dense immunochemotherapy and early systemic CNS prophylaxis (www.ClinicalTrials.gov, number NCT01325194). Median pretreatment ALC was 1.40 × 10⁹/l (range, 0.20-4.95), AMC 0.68 × 10⁹/l (range, 0.10-2.62), and LMR 2.08 (range, 0.10-12.00). ALC did not correlate with tumor-infiltrating lymphocytes, AMC did not correlate with tumor-associated macrophages, and neither ALC nor AMC correlated with survival. However, low LMR (<1.72) translated to unfavourable progression-free survival (PFS) (5-year PFS 70% vs. 92%, p = 0.002) and overall survival (OS) (5-year OS, 77% vs. 92%, p = 0.020). In the patients with low LMR, relative risk of progression was 4.4-fold (95% confidence interval [CI] 1.60-12.14, p = 0.004), and relative risk of death was 3.3-fold (95% CI 1.18-9.50, p = 0.024) in comparison to the patients with high LMR. We conclude that low LMR is an adverse prognostic factor in uniformly treated young patients with high-risk aggressive large B-cell lymphoma.