Is medulloblastoma associated with systemic immunomodulation? – A comparative analysis of preoperative inflammatory markers

BACKGROUND: We attempt to compare preoperative inflammatory markers among children with medulloblastoma and pilocytic astrocytoma and establish their diagnostic efficacy to distinguish these tumors. METHODS: Children (<18 years) with biopsy-proven medulloblastoma and pilocytic astrocytoma operated at our institute from January 2012 to January 2018 were enrolled in this study. The hematological parameters were compared between the two groups and with healthy controls. Children with a history of disease or medications that may confound these parameters were excluded from the study. Receiver operator characteristic curves were made to assess the diagnostic accuracy of markers found to be significant. RESULTS: Patients with medulloblastoma were found to have higher neutrophil-lymphocyte ratio (NLR), derived neutrophil-lymphocyte ratio (dNLR), platelet-lymphocyte ratio (PLR), and platelet counts compared with pilocytic astrocytoma. Absolute lymphocyte count (ALC) was significantly lower in medulloblastoma group as compared to healthy controls but not with pilocytic astrocytoma. NLR and dNLR demonstrated maximum diagnostic accuracy in distinguishing patients with medulloblastoma from healthy controls and pilocytic astrocytoma. Using a cutoff of 2.45 for NLR distinguishes medulloblastoma from healthy controls as well as pilocytic astrocytoma with a sensitivity of 75.5% and specificity of 66.7%. Similarly, dNLR cutoff of 1.47 distinguishes medulloblastoma from healthy controls with a sensitivity of 83% and specificity of 76% and a cutoff of 1.53 distinguishes medulloblastoma from pilocytic astrocytoma with a sensitivity of 81.1% and specificity of 81.8%. Combination of NLR and dNLR performed only marginally better than individual variables with area under the curve being 0.856 for medulloblastoma versus healthy controls and 0.86 for medulloblastoma versus pilocytic astrocytoma. CONCLUSION: NLR and dNLR can be used as a preoperative predictive marker in medulloblastoma. There is decreased ALC in patients with medulloblastoma contributing to raised NLR and dNLR suggestive of systemic immunosuppression.