537P - S100A9 serum levels are associated with survival prognosis in patients with brain metastases

Background

Brain metastases (BM) are a clinical challenge in oncology. Further insight on pathobiology is the basis for new treatment approaches. Recently, S100A9 has been postulated as a novel potential biomarker for therapy resistance to radiotherapy in preclinical BM models. Therefore, we aimed to explore S100A9 levels in a real-life BM patient cohort.

Methods

S100A9 protein expression was measured in the serum of patients treated at the Medical University of Vienna between 2019-2023 using an enzyme-linked immunosorbent assay (ELISA) to correlate its levels with clinicopathological parameters. Sample concentrations below the lower limit of quantification (LOQ) were treated as 50% of LOQ´s concentration and considered as non-quantifiable. Samples with a concentration above the upper limit of quantification were remeasured in dilutions.

Results

80 patients (39% male; 61% female) with BM (n=69) and without BM (n=11) were included in this pre-liminary analysis. Median serum level of S100A9 was 23 pg/mL (IQR 16-97 pg/mL). No difference in median S100A9 levels were observed between patients with BM (23 pg/mL, IQR 16-114) and without BM (23 pg/mL, IQR 15-41) at time of blood sampling (p=0.7). Furthermore, no difference was found in median S100A9 levels in BM patients according to primary tumor’s origin (lung cancer 23 pg/mL vs. breast cancer 16 pg/mL, p=0.6) or radiated versus non-radiated BM (37 pg/mL vs. 23 pg/mL, p=0.3). Median overall survival of patients with quantifiable S100A9 levels were significantly longer than patients with non-quantifiable S100A9 serum levels (HR 2.05; p=0.05).

Conclusions

Based on the results of these pre-liminary data, S100A9 levels did neither correlate with BM diagnosis, primary tumor’s origin nor previously applied radiotherapy. However, detected S100A9 levels correlated with survival analysis in this real-life BM patients. Further studies are currently ongoing to further evaluate S100A9 as a diagnostic and predictive biomarker in larger real-world patient cohorts.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

A.M. Starzer: Financial Interests, Personal, Speaker, Consultant, Advisor: AstraZeneca; Financial Interests, Personal, Other, Travel costs: Pharma Mar, MSD, Lilly. M. Preusser: Financial Interests, Personal, Speaker, Consultant, Advisor: Bayer, Bristol Myers Squibb, Novartis, Gerson Lehrman Group (GLG, CMC Contrast, GSK, Mundipharma, Roche, BMJ Journals, MedMedia, AstraZeneca, AbbVie, Lilly, Medahead, Daiichi Sankyo, Sanofi, Merck Sharp & Dome, Tocagen, Servier. A.S. Berghoff: Financial Interests, Personal, Research Funding: Daiichi Sankyo, Roche; Financial Interests, Personal, Advisory Board: Roche Bristol Meyers Squibb, Bristol Meyers Squibb, Merck, Daiichi Sankyo, AstraZeneca, CeCaVa; Financial Interests, Personal, Other, Travel costs: Amgen, AbbVie, Roche. All other authors have declared no conflicts of interest.