Purpose: Matrix metalloproteinase 9 (MMP-9) has been shown to induce glioblastoma and brain metastases (BM) development and spread. However, its clinical significance for monitoring disease progression has yet to be established. This study evaluates intra-tumoral and sera MMP-9 levels and their influence on glioblastoma and BM patients' overall survival (OS).
Methods: 92 tumor and pre-operative sera samples were obtained from the brain tumor bank of the neurosurgery department at Soroka University Medical Center from patients who underwent tumor resection between 2015 and 2021. Clinical and imaging data from 27 glioblastoma and 30 BM patients were analyzed, and their MMP-9 levels and activity were measured and compared with meningioma patients and healthy subjects. Survival analyses were performed to examine the impact of MMP-9 level, activity, and clinical parameters on patients' OS.
Results: Glioblastoma and BM patients demonstrated increased median intra-tumoral MMP-9 levels (8ng/ml and 4ng/ml, respectively, p<0.001), activity, and pre-operative sera levels (2.8ng/ml and 1.8ng/ml, respectively, p<0.001). MMP-9 was specifically detected within and between glioblastoma cells and tumor endothelia. High intra-tumoral and sera MMP-9 levels, but not its activity, were linked to decreased OS in glioblastoma and BM patients (15.8 versus 8.4 months, p=0.022). Sera MMP-9 was readily measured in patient sera.
Conclusions: This study suggests that intra-tumoral and sera MMP-9 can assist in identifying glioblastoma and BM recurrence/progression and that high intra-tumoral and/or sera MMP-9 levels at diagnosis correlate with significantly shorter patient OS. Importantly, sera MMP-9 could be longitudinally and non-invasively monitored in those patients and, once rising, may indicate tumor progression.
