8332 Genotype/Phenotype Profile Of Pheochromocytoma/Paraganglioma Patients In A Single Tertiary Referral Center Of South Texas

Abstract Disclosure: V. Desai: None. M.A. Escobar Vasco: None. C. Estrada-Zuniga: None. B. Landry: None. H. Gonzalez-Cantu: None. D. Pruthi: None. F. Tozzi: None. J. Ferrell: None. M. Kitano: None. C. Solis-Herrera: None. J.M. Bruder: None. S. Raghunathan: None. P.L. Dahia: None. Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors. Nearly 40% of patients with PPGLs have a heritable germline mutation and around 30% carry somatic mutations in one of >20 known susceptibility genes. 15-20% of cases can progress to metastatic disease. Recently, ethnic differences have been suggested in PPGLs and support further evaluation of ethnically diverse cohorts which can offer guidance for surveillance and patient care. Goal: The objective of this study is to identify genetic and clinical features of patients with a diagnosis of PPGL in predominant ethnic groups located in a single tertiary referral center of South Texas that is a designated Pheo-Para Alliance Clinical and Research Center of Excellence. Methods: Medical records were utilized to obtain demographic and clinical data, including age at diagnosis, gender, ethnicity, family history, tumor location, metastasis, clinical disease vs. carrier status, and genotype from patients enrolled in an IRB-approved repository. Results: 62 index patients who were diagnosed with PPGL or had a pathogenic germline mutation with no clinical disease were enrolled between 2006 to 2023. Patients were predominantly Caucasian (n=30/59, 50.8%) and Hispanic (n=24/59, 40.6%). In the Hispanic group, twenty-one were diagnosed with PPGL and three were asymptomatic carriers. This group had an average age of 38.3 years (range, 13-77), 85.7% had pheochromocytomas (11.1% were bilateral), 14.3% were metastatic, 16.7% had a positive family history, and 65% had an identifiable germline mutation. The most commonly mutated genes in Hispanics were VHL (n=5), SDHx (n=5), and EPAS1 (n=3). In the Caucasian group, thirty patients were diagnosed with PPGL and three were asymptomatic carriers. The average age for Caucasians was 46.4 years (range, 19-80). 23% had a positive family history, 66.7% had pheochromocytoma, 22.2% had metastatic disease, and 77.3% had a germline mutation. The most common genotype in Caucasians was SDHx (n=12) followed by NF1 (n=4). Conclusion: In this PPGL cohort, Hispanic patients tended to be younger at diagnosis, have lower proportion of SDH germline mutations and higher frequency of somatic mutations compared to Caucasians. This preliminary observation should inform further investigation into PPGL genotype-phenotype associations across ethnic groups toward improving surveillance and patient care. Presentation: 6/2/2024