Clinical and Biochemical Characteristics of Patients with Somatic HRAS -mutant Pheochromocytoma and Paraganglioma

Objective The frequency of pathogenic variants (PVs) in HRAS in Caucasian populations with pheochromocytoma and paraganglioma (PPGL) is significantly lower than that in Chinese, which reflects the ethnic difference in genetic landscape. However, the clinical and biochemical characteristics of patients with HRAS-mutant PPGL are rarely reported. This study explored the clinical and biochemical profiles of Chinese patients with HRAS-mutant PPGL. Design This is a retrospective analysis of clinical and biochemical characteristics of patients with PPGL (N = 717). Methods Data on demographics, tumor characteristics, blood/urine biochemistry, preoperative preparation, intraoperative hemodynamics, and perioperative complications were analyzed in patients with HRAS-mutant and non-HRAS PPGL. Results A total of 111 (15.5%) patients were with PPGL due to PVs in HRAS. Patients with HRAS-mutant PPGL had higher plasma metanephrine levels, an increased incidence of catecholamine-associated signs and symptoms (CAS), intraoperative hemodynamic instability (IHI) and intensive care unit (ICU) transfer right after surgery compared to those with non-HRAS tumor. Despite with similar tumor size, patients with HRAS-mutant PPGL had significantly higher plasma metanephrine levels, a higher incidence of presenting CAS and IHI than those with tumors due to PVs in other genes associated with kinase pathways. A significantly high catecholamine content in HRAS-mutant PPGL was associated with high levels of enzymes of catecholamine metabolism such as tyrosine hydroxylase and phenylethanolamine N-methyltransferase, which was independent of tumor locations. Conclusions Patients with HRAS-mutant PPGL have higher plasma metanephrine levels and a higher risk of IHI and ICU transfer, which therefore requires personalized perioperative managements.