Diagnostic Utility of Pre-Intervention Inflammatory Markers in Patients with Glioma Vs Brain Metastasis

Glioma and brain metastatic tumors are the most common neoplasms encountered in the central nervous system (CNS) and continue to be the major cause for mortality and morbidity. Histological examination of tumor tissue through biopsy or resection serves as a definitive diagnosis of glioma and brain metastasis, whereas contrast tomography (CT) and magnetic resonance imaging (MRI) are supplemental tests for disease staging and treatment response monitoring. However, these are expensive and collecting specimens for histopathological studies are invasive. Currently, studies have shown that cancer cells and the immune system have interaction in several steps in tumorigenesis hence involvement of the inflammatory markers. Tumors have a tumor microenvironment (TME) which contains not only cancer cells but also noncancerous cell types including endothelial cells, pericytes, fibroblasts, and immune cells such as neutrophils, lymphocyte, monocytes and platelets. ^[1] Thus, studies investigated the relationship of these cells to other tumors with note that preoperative or pre-intervention levels of neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR) are new markers for diagnosis and predicting prognosis of tumors ^{[2, 3, 4, 5]}. This study focuses on the diagnostic utility of pre-intervention inflammatory markers in comparing glioma and brain metastasis. This is a retrospective study of patients admitted in Jose R. Reyes Memorial Medical Center from January 2016 to December 2022. There were 91 patients included, 47 were diagnosed with glioma while 44 were diagnosed with brain metastasis. Statistical analysis based on quartile values of the inflammatory markers yielded significant difference among patients with glioma and brain metastasis. NLR cut-off value at <3.95 has the highest specificity at 88.64% and sensitivity at 34.04% in glioma patients. PLR cut off value at <12.47 has the highest specificity at 90.91% and sensitivity at 38.30% in glioma patients. Hence, low NLR and PLR favors the diagnosis of glioma while high NLR and PLR favors the diagnosis of brain metastasis.