Efficacy of aspirin for sporadic vestibular schwannoma: a meta-analysis

Background Pharmacologic treatment of vestibular schwannomas (VSs) may increase the success of conservative management for small lesions, and offer an alternative to surgery and stereotactic radiotherapy in symptomatic cases in the high-risk population. Agents that have been studied include aspirin (ASA), but the results of the preliminary studies have been conflicting. In this study, we aimed to systematically review the evidence on the effect of ASA intake on tumor growth in patients with VSs. Methods Pubmed, Cochrane, Scopus, Embase, ClinicalTrials.gov, and Web of Science were searched for studies comparing VS tumor growth in patients with aspirin intake and those without. Random-effect meta-analysis was used to evaluate the outcomes in terms of linear and/or volumetric tumor growth. Results Four retrospective cohort studies were included in the meta-analysis. No significant difference was found in tumor growth between VS patients with aspirin intake and those without. This result held true for the analysis of linear tumor growth (OR 1.23; 95% CI 0.49, 3.10), volumetric tumor growth (OR 1.41; 95% CI 0.36, 5.59), and both combined (OR 1.02; 95% CI 0.56, 1.86). Conclusions Our meta-analysis suggests that there is insufficient evidence to recommend ASA therapy in patients with VSs. High-quality randomized controlled trials are warranted to determine the efficacy of this drug in reducing VS tumor growth.