High Soluble P-Selectin and Low Platelet Count as Thrombosis Risk Markers in Glioma Patients.

Glioma patients are at high risk for venous thromboembolism (VTE). However, predictive laboratory parameters have not been identified. High platelet count (PLC) and increased soluble P-selectin (sP-selectin) have been reported as risk factors in cancer patients, so we investigated sP-selectin and PLC as risk markers in glioma patients.

The Cancer and Thrombosis Study (CATS) is a prospective observational study, whose endpoint is the occurrence of objectively confirmed VTE. sP-selectin was measured in the third week after neurosurgical intervention using a human sP-selectin Immunoassay (R&D Systems®, Minneapolis, USA). Multivariable Cox regression analysis was applied to calculate hazard ratios (HR) for VTE, including PLC, sP-selectin, age, sex and type of surgery.

140 patients with newly diagnosed high grade glioma were analysed (52 women; median age 54.5 years [interquartile range (IQR): 42.8-5.1]) during a median observation time of 309 (range: 3-1664) days. Twenty patients developed VTE (6 women, 14 men), of which 2 events were fatal pulmonary embolisms. The cumulative probability of VTE was 10% at six and 15% at twelve months. sP-selectin levels (ng/mL) were higher in patients with VTE compared to those without (median=51.8, IQR: 36.9–66.0 versus median=38.8, IQR: 30.7–52.1, p=0.011). Interestingly, PLC (G/l) was significantly lower in patients with (median=214, IQR: 166-248) than in those without VTE (median=255, IQR: 200-327; p=0.011). In multivariable regression analysis high sP-selectin (75^th percentile: 55.1ng/mL) and low PLC (25^th percentile: 198G/L) were significant risk markers of VTE (HR=3.4, 95% CI 1.3-9.0, and HR=3.3, 95% CI 1.2-8.8, respectively).

Our study revealed two strong predictive markers for VTE in glioma patients. Elevated sP-selectin is associated with a three-fold increased risk of thrombosis. In contrast to patients with other solid tumours, in glioma patients low PLC is associated with increased thrombosis risk.

Pabinger:Amgen Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees.