Initial lymphocyte to monocyte ratio as a surrogate marker of survival in adults with de novo non-m3 acute myeloid leukemia

• Main Authors: Ahmed Embaby, Ayman Fathy, Ahmad Baraka, Mohamed El Akad, Mai Gobran, Haitham Elsheikh
• Format: Article
• Language: English
• Published: PAGEPress Publications 2020-09-01
• Series: Hematology Reports
• Online Access: https://www.pagepress.org/journals/index.php/hr/article/view/8908

Introduction: Low absolute lymphocyte/ monocyte ratio (LMR) at presentation has been associated with clinical outcome in various types of hematological malignancies including multiple myeloma, Hodgkin's and non- Hodgkin's lymphomas, but to the best of our knowledge, no data are available on its role in acute myeloid leukemia (AML). This study aims to investigate the prognostic significance of LMR at diagnosis, as a simple biomarker merging an index of host immune homeostasis with tumor microenvironment, in de novo AML. Methods: In this prospective cohort study, we evaluated 100 previously untreated adult patients with de novo non-M3 AML, aged 18 years or older and treated at Clinical Hematology Unit, Internal Medicine department at Zagazig University Hospitals, from September 2016 to August 2019. The estimated initial LMR cut-off value for survival outcome generated by receiver operating characteristic (ROC) curve was (3), had an AUC of 0.613 (95% CI, 0.511 to 0.709) with a sensitivity of 73.33% (95% CI, 60.3 - 83.9%) and a specificity of 55% (95% CI, 38.5 - 70.7%), P= 0.047. Disease-free survival and overall survival (DFS and OS) were estimated using the Kaplan-Meier method and two-tailed log-rank; The Cox proportional hazards model was used to evaluate LMR as a prognostic factor on univariate and multivariate analyses. Results: The median follow-up was 7.7 months (range, 0.5-33.2 months), patients with lower LMR (≤3) had a lower complete remission rate, 3-year OS and 3-year DFS when compared to patients with LMR >3, respectively (51.6% versus 73.7 %, P=0.029; 0.0 versus 44.9 %, P=0.03; and 0.0 versus 45 %; P=0.021, respectively). Moreover, death as well as relapse rates were significantly higher in patients with LMR ≤3, (71.0%), and (62.5%), versus (42.1%) and (12.6%) in those with LMR>3, P= 0.004, and 0.009, respectively. On univariate and multivariate analyses considering different variables affecting survival, we found that lower LMR at diagnosis remained an independent adverse predictor of DFS only (HR: 4.51 [95%CI: 1.57-12.97], P=0.005). Conclusions: We are the first to report that low initial LMR is an independent adverse prognostic factor for DFS in AML patients. Being simple, inexpensive and easily obtained from routine CBC for most patients, it could be a novel additional prognostic tool for AML. But, it should be revalidated in multicentre prospective studies with consideration of patients’ racial/genetic information, as well as, the subpopulations of monocytes and lymphocytes. Keywords: Acute Myeloid Leukemia- Absolute Lymphocyte/Monocyte Ratio (LMR)- Survival Outcome- prognosis.