Tracking tumor alteration in glioma through serum fibroblast activation protein combined with image

Abstract

Abstract Purpose Detecting tumor progression remains difficult in patients with glioma. Fibroblast activation protein (FAP) in gliomas has been showed to promote tumor progression. Glioma-circulating biomarkers have not yet been used in clinical practice. This study seeks to evaluate the feasibility of glioma detection using a serum FAP marker. Methods We adopted enzyme-linked immunoadsorbent assay (ELISA) to determine serum FAP level in 87 gliomas. The relationship between preoperative serum FAP levels and postoperative pathology, as well as molecular pathology was investigated. Serial FAP tests were performed in 33 malignant gliomas to see if they could track the disease when compared to image findings. Immunohistochemistry was performed on four gliomas using a FAP-specific antibody to confirm FAP expression in tumors. Therelationship between tumor burden as determined by volumetric analysis and serum FAP level was investigated. Results Serum FAP was significantly elevated in a large proportion of gliomas, was closely related to histopathology and molecular pathology, and longitudinally fluctuated and varied with the disease stage. The significant increase in serum FAP was associated with tumor progression and/or worsening symptoms. Conclusions Serum FAP can be used to detect the disease as a biomarker. Its detection in conjunction with MR imaging may allow for more precise and immediate diagnosis.