The Evaluation of Diagnostic, Prognostic, and Predictive Role of Hematologic Inflammatory Indices NLR, PLR, and LMR in Common Solid Tumors

Abstract

Background: Solid tumors are one of the leading causes of cancer-related deaths. Measurable combined inflammatory markers in the blood, which indicate the inflammatory response, play a crucial role in managing patients with malignancies. These markers have been validated as less invasive, practical, and cost-effective tools in the clinical decision-making process. The aim of this study is to evaluate the predictive value of inflammatory markers based on complete blood count (CBC), including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) in major solid tumors, including breast, lung, colorectal, and prostate cancers, due to their high prevalence and strong evidence base. Recent Findings: In this study, studies from 2015 to June 2025 were searched in Google Scholar, PubMed, and Scopus using keywords such as neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, prognosis value, predictive value, diagnosis value, lung cancer, colon cancer, prostate cancer, and breast cancer. Findings indicate that elevated NLR and PLR, alongside reduced LMR, are commonly associated with advanced disease, poorer survival, and diminished response to treatment, though the strength of evidence varies by cancer type. Limitations across studies include retrospective design, inconsistent cut-off values, and confounding factors such as comorbidities and treatment regimens. Conclusion: Current evidence suggests that NLR, PLR, and LMR have significant potential as accessible biomarkers for risk stratification and treatment monitoring in common solid tumors. However, lack of standardization in methodology and cut-off definitions limits their widespread clinical implementation. High-quality prospective studies are needed to establish unified thresholds and clarify their role alongside established biomarkers.