Immature granulocytes as novel blood-based biomarkers for brain tumours: A prospective case-control study

Chronic inflammation within the tumour microenvironment has been recognised as a key factor in the initiation and progression of tumours. Brain tumours significantly affect patient survival and quality of life. Identifying an accessible biomarker for diagnosing and monitoring brain tumours could support earlier detection and intervention.

This single-centre prospective observational study included 334 patients with histopathologically confirmed intracranial tumours and 299 age- and sex-matched controls with normal brain magnetic resonance imaging findings. Blood samples were evaluated for levels of procalcitonin, C-reactive protein (CRP), plateletcrit (PCT), platelet distribution width (PDW), neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), mean platelet volume (MPV) and both the absolute count and percentage of immature granulocytes (IGs). The diagnostic accuracy, sensitivity and specificity of these parameters in identifying intracranial tumours were statistically analysed.

Procalcitonin, CRP, NLR, RDW and both the absolute count and percentage of IGs were significantly elevated in patients with brain tumours compared to the control group. In the ROC analysis, IG percentage demonstrated the highest AUC and specificity, whereas NLR showed the highest sensitivity. Procalcitonin, NLR, RDW and both IG count and percentage were significantly higher in Grade III-IV tumours than in grades I-II.

Readily available and cost-efficient inflammatory markers may support the detection and follow-up of brain tumours. In particular, immature granulocyte percentage and neutrophil to lymphocyte ratio demonstrated complementary diagnostic performance, favouring specificity and sensitivity, respectively. Integration of such blood-based indices with molecular classifiers could enhance risk stratification and guide personalised neuro-oncological management.