Increased preoperative levels of circulating erythrocytic hemoglobin might predict high-grade histology (WHO grade 2-3) in falcine and parasagittal meningiomas.

Background: Falcine/parasagittal lesions account for the largest rate of high-grade (WHO grade 2-3) lesions. The ability to preoperatively estimate the tumors' grade and outcome would be of great value in customizing treatment.

Methods: This is a single-center, retrospective study designed to assess the pre-operative peripheral blood markers' diagnostic and prognostic role in patients harboring falcine (FM) and parasagittal (PM) high-grade meningiomas. N=116 patients undergoing surgical resection were included. A propensity score-matched analysis accounted for gender imbalances in low-grade (LG) vs. high-grade (HG) cohorts.

Results: Seventy-three (N.=73) FM (63%) and 43 PM (37%) lesions were included. Patients harboring HG lesions showed significantly higher Hb levels than LG (mean 14.5±1.40 vs. 13.5±1.16 g/dL, P<0.001). Multivariate analysis controlling for demographics, lesion characteristics, blood markers, and steroid dose confirmed preoperative Hb as an independent predictive value of lesion grade (OR 1.75, 95% CI:1.01-3.07, P=0.04). Accordingly, patients showing increased Hb levels >15.4 g/dL achieved shorter OS (60.4 months, 95% CI: 14.7-106.1 vs. 134.7 months, 95% CI: 111.2-158.2) compared to patients with lower Hb values, P<0.001. Data were confirmed in matched cohorts.

Conclusions: Increased levels of circulating erythrocytic hemoglobin might be independent predictors for high-grade histology and be associated with shorter overall survival in falcine and parasagittal meningiomas.