Session Item

RTT track: Treatment planning and dose calculation / QC and QA
9345
Poster
RTT
11:02 - 11:10
Blood plasma based risk stratification of glioblastoma patients
PH-0359

Abstract

Blood plasma based risk stratification of glioblastoma patients
Authors: Fleischmann|, Daniel(1,2,3)*[daniel.fleischmann@med.uni-muenchen.de];Unger|, Kristian(1,4,5);Ruf|, Viktoria(6);Heider|, Theresa(4,5);Hess|, Julia(1,4,5);Drexler|, Guido(1);Herms|, Jochen(6);Thon|, Niklas(2,7);Kreth|, Friedrich-Wilhelm(2,7);Tonn|, Jörg-Christian(2,7);Zitzelsberger|, Horst(1,4,5);Lauber|, Kirsten(1,2,5);Belka|, Claus(1,2,5);Niyazi|, Maximilian(1,2,5);
(1)University Hospital- LMU Munich, Department of Radiation Oncology, Munich, Germany;(2)German Cancer Consortium DKTK, partner site Munich, Munich, Germany;(3)German Cancer Research Center DKFZ, Deutsches Krebsforschungszentrum, Heidelberg, Germany;(4)Helmholtz Zentrum München, Research Unit of Radiation Cytogenetics, Neuherberg, Germany;(5)Helmholtz Zentrum München, Clinical Cooperation Group Personalized Radiotherapy in Head and Neck Cancer, Neuherberg, Germany;(6)Faculty of Medicine- LMU Munich, Institute of Neuropathology, Munich, Germany;(7)University Hospital- LMU Munich, Department of Neurosurgery, Munich, Germany;
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Purpose or Objective

Risk stratification in IDH-wildtype glioblastoma patients is limited, as MGMT methylation status is the only prognostically relevant biomarker available and no liquid biopsy markers are in clinical use. Recently, we established a prognostic miRNA signature in glioblastoma tumour tissue. Here, we prospectively analysed the 4-miRNA signature in blood plasma samples to assess its value as a prognostic liquid biopsy marker for glioblastoma patients.

Material and Methods

Glioblastoma patients with IDH-wildtype between 18 and 70 years of age with the indication for conventionally fractionated radiochemotherapy were enrolled prospectively. Blood plasma samples were obtained prior to radiochemotherapy and were examined using miRNA microarrays on the expression levels of the four miRNAs hsa-let-7a-5p, hsa-let-7b-5p, hsa-miR-125a-5p and hsa-miR-615-5p. Based on the previously established weighting factors of the expression levels, patients were divided into a high-risk and a low-risk group. Kaplan-Meier analysis was performed for high- and low-risk patients to assess the progression-free survival from the beginning of radiochemotherapy until first diagnosis of progression on MRI.

Results

The 4-miRNA risk score was assessed in plasma samples from 22 glioblastoma patients (median age 55 years; 14 male, 8 female; 6 definitive, 16 adjuvant cases; MGMT promotor methylation in 13/22 cases) and resulted in 10 low-risk and 12 high-risk cases. Progression-free survival was significantly longer in low-risk patients (mean 22.6 months (95%-CI 17.1 – 28.1 months)) than in high-risk patients (mean 9.6 months (95%-CI 6.3 – 12.9 months), p=0.005) with a hazard ratio of 5.6 (95%-CI 1.5 – 21.7). The median progression-free survival has not yet been reached in low-risk patients after a median follow-up of 19 months.

Conclusion

Blood plasma based risk stratification through the 4-miRNA risk score shows strong differences in progression-free survival of glioblastoma patients.