The influence of endothelial hyperplasia on pseudoprogression development in patients with glioblastoma

Abstract

Introduction/Objective. Pseudoprogression represents an enlarging contrast-enhancing lesion that occurs after chemoradiation and stabilizes with time without any changes in the therapeutic procedure. This phenomenon is highly significant, because it can have influence on further therapeutic procedures; however, precise criteria for pseudoprogression diagnosis have not yet been defined. The main goal of this study is to examine the endothelial hyperplasia influence on pseudoprogression. Methods. We analyzed a group of 106 patients with glioblastoma who had undergone surgical treatment from 2010?2012, at the Clinic of Neurosurgery, Clinical Center of Serbia, who received Stupp protocol. Pre- and post-treatment imaging was evaluated using RANO criteria. Lesions that improved or stabilized were defined as pseudoprogression, and lesions that progressed were defined as true progression. Endothelial hyperplasia was identified based on the hematoxylin and eosin pathohistological examination. Results. Thirty-two (30.2%) of the patients were diagnosed with pseudoprogression. Endothelial hyperplasia was observed in 51 (48.1%) of glioblastoma tissue samples, and 28 (87.5%) of all the patients with pseudoprogression were found to have endothelial hyperplasia. The group of 51 (68.9%) patients without pseudoprogression did not show the presence of endothelial hyperplasia. Statistical analysis showed significantly higher incidence of pseudoprogression in patients with endothelial hyperplasia. (?2 = 26.269, p < 0.01) Conclusion. Taking into account that there are no precise diagnostic methods that could determine the presence of endothelial hyperplasia with certainty, it could be an indicator, as a pathohistological entity, of a higher likelihood of pseudoprogression, which could be used in everyday clinical practice. In order to reach definite conclusions, we believe it is necessary to conduct prospective controlled studies with larger sample sizes.