(A858) Rates of Concurrent Cancer in Patients with Sporadic Vestibular Schwannoma

Introduction: Vestibular schwannomas (VS) are the most common tumor of the cerebellopontine angle with an incidence of about 1 out of 100,000 in the US. The rate of concurrent cancer diagnosis in patients with VS is unknown. Our study aims to explore the frequency of cancer diagnoses in patients with VS to guide future work exploring common tumor genesis pathways.

Methods: This is a retrospective cohort study of adults diagnosed with VS at a tertiary care hospital from January 1990 through June 2023. Patient demographics, VS size, laterality, and any cancer diagnosis during the patient’s lifetime were obtained through chart review. T-test and chi-squared analysis were performed in R studio to identify differences between the groups of VS patients with and without cancer. Multivariable regressions will be performed.

Results: Preliminary data of 379 patients found 128 patients (34%) had a cancer diagnosis during their lifetime. We stratified VS patients into two groups: VS+cancer history and VS only. Both groups had similar demographics. The VS only mean age at diagnosis of VS was 59 years (±14) while that of VS+cancer history was 65 years (±13), p< 0.05. Diagnoses of VS and cancer were an average of 8.7 years (±11.1) apart. Most had their cancer diagnosis first. The mean tumor diameter at time of diagnosis was significantly different between the two groups: VS only at 1.43cm (±1.02) versus VS+cancer history at 1.23cm (±0.87), p< 0.05. 19 types of cancer were identified. The most common malignancies were breast (20%), prostate (13%), and melanoma (11%).

Conclusions: The rate of historical or co-incidental cancer in VS is not trivial. Those with concurrent VS and cancer were diagnosed with VS at a later age with smaller tumors. This may be due to increased surveillance imaging that would identify a smaller VS. When compared to the general population’s probability of developing cancer, our cohort differed in that more patients had concurrent cutaneous malignancies than colon malignancies. Further exploration into common tumor genesis pathways could be explored as means to better understand the genetics of sporadic VS.