Association of Metformin With Volumetric Tumor Growth of Sporadic Vestibular Schwannomas

The Effect of Metformin on Vestibular Schwannoma Growth: A Systematic Review and Meta-analysis

OBJECTIVES

To systematically review and evaluate metformin's potential impact on vestibular schwannoma (VS) growth.

DATA SOURCES

PubMed, Cochrane Library, and Embase.

REVIEW METHODS

A retrospective cohort study was performed on sporadic VS patients undergoing initial observation who had at least two magnetic resonance imaging studies. Patients were stratified by metformin use during the observation period. Primary endpoint was VS growth, defined as at least a 2 mm increase in diameter. Survival free of tumor growth was evaluated between groups. Systematic review and meta-analysis were performed to produce a pooled odds ratio [OR]. Study heterogeneity was assessed and post-hoc power analysis was performed.

RESULTS

A total of 123 patients were included, of which 17% were taking metformin. Median patient age was 56.6 years (range, 25.1-84.5). There were no statistically significant differences between the groups. Survival analysis did not demonstrate a statistically significant difference in time to VS growth between groups (hazard ratio = 0.61, 95% confidence interval [CI] = 0.29-1.29). Furthermore, logistic regression analysis did not demonstrate a statistically significant difference between groups in the odds of VS growth (OR = 0.46, 95% CI = 0.17-1.27). Systematic review identified 3 studies. Meta-analysis suggested that metformin reduces the odds of developing VS growth (pooled OR = 0.45, 95% CI = 0.29-0.71). Studies demonstrated low between-study heterogeneity. Power analysis demonstrated a sample size of 220 patients with equal randomization would be required to prospectively identify a true difference with 80% power.

CONCLUSIONS

Metformin use may reduce the odds of VS growth. A randomized trial would be ideal to identify an unbiased estimate of metformin's effect on VS growth. Laryngoscope, 133:2066-2072, 2023.

Mining the Biomarkers and Associated-Drugs for Esophageal Squamous Cell Carcinoma by Bioinformatic Methods

Esophageal squamous cell carcinoma (ESCC) showed limited treatment outcome and poor prognosis. This study aimed to screen potential biomarkers and drugs in ESCC. Firstly, GSE26886, GSE111044 and GSE77861 were downloaded from the Gene Expression Omnibus (GEO) database. Next, the differentially expressed genes (DEGs) between cancer and noncancerous tissues were analyzed by the GEO2R. The Gene Ontology (GO) annotation, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation, the protein-protein interaction (PPI) analysis and hub genes screened were conducted by some bioinformatic methods, respectively. Lastly, the hub genes and potential drugs were verified by the GEPIA2 and the QuartataWeb database. The results showed that 13 up-regulated genes and 81 down-regulated genes were identified. In GO terms, DEGs were mainly associated with cell proliferation, cell migration and cell differentiation. DEGs did not cluster into the KEGG pathway. After hub genes validated, nine genes (FLG, COL1A1, COL1A2, PSCA, SCEL, PPL, ACPP, CNFN, and A2ML1) expression trends showed no change. Moreover, higher COL1A1 or COL1A2 expression for ESCC patients showed poor prognosis. Finally, five drugs used for promoting blood coagulation were identified. Probably, these drugs could show anticancer effects by promoting blood coagulation or inhibiting vascular formation in cancers, which offers a novel idea for the treatment of ESCC.