(810) Association Between Treatment of Pro-Inflammatory Conditions and Vestibular Schwannoma Risk

Introduction: Vestibular schwannoma (VS) is a benign cranial nerve tumor with unclear etiology. Prior literature has suggested a role for inflammation and immune dysregulation in the development of VS. This study evaluates whether treatment of pro-inflammatory conditions—type 2 diabetes mellitus (DM2), dyslipidemia, and rheumatoid arthritis (RA)—alters the likelihood of subsequently developing VS later in life. To our knowledge, this represents the largest study of its kind examining treatment effects on VS risk.

Methods: Using the TriNetX Research Network, we conducted a retrospective cohort study comparing treated and untreated patients with DM2, dyslipidemia, or RA, and subsequent VS rates. DM2 treatments included metformin, insulin, DPP-4 and SGLT2 inhibitors, sulfonylureas; dyslipidemia treatment included statins, fibrates, ezetimibe, niacin; and RA treatment included DMARDs, NSAIDs, and corticosteroids. Each treated cohort was propensity score–matched 1:1 to untreated controls, excluding patients with prior VS diagnoses. DM2 and dyslipidemia models were mutually adjusted.

Results: Among 2,907,162 matched patients per diabetes group, the risk of VS was similar between treated and untreated cohorts (0.019% vs. 0.018%, p = 0.40). In the dyslipidemia group (6,309,934 patients per group), treatment was associated with a higher risk of VS (0.030% vs. 0.022%; OR = 1.32, 95% CI: 1.23–1.41; p < 0.0001). In the rheumatoid arthritis group (247,884 patients per group), treated patients had an elevated VS risk compared to untreated patients (0.046% vs. 0.022%; OR = 2.07, 95% CI: 1.50–2.86; p < 0.0001).

Conclusions: Treatment of DM2 did not significantly impact VS risk. Surprisingly, treatment for dyslipidemia and RA was associated with increased risk, potentially due to confounding by severity, treatment selection, or surveillance bias. These findings warrant further investigation.