Demographic and clinical factors impacting survival in malignant pheochromocytoma: A population-based analysis.

Abstract

e22605 Background: Malignant pheochromocytoma is a rare and potentially aggressive neuroendocrine tumor arising from chromaffin cells. While overall survival (OS) is often favorable compared to other malignancies, a subset of patients experiences progressive disease. Existing literature has primarily focused on clinical and pathological prognostic factors, such as tumor size, location, and genetic markers. However, a significant gap remains in the large-scale epidemiological assessment of how demographic and socioeconomic factors influence patient outcomes. Furthermore, real-world evidence on the impact of specific treatment modalities, particularly in the context of these demographic variables, is limited. This study utilizes a national population-based registry to investigate the association between demographic factors, treatment approaches, and survival in malignant pheochromocytoma. Methods: Patients diagnosed with malignant pheochromocytoma from 2000 through 2022 were identified from the Surveillance, Epidemiology, and End Results (SEER) database using the International Classification of Diseases for Oncology, Third Edition (ICD-O-3) histology code 8700/3. Overall survival was analyzed using Cox proportional hazard regression models in GraphPad Prism. Results: The study cohort included 996 patients. Over a median follow-up of 22 months, 305 deaths occurred. In terms of demographic factors, Older age (≥65 years) was associated with significantly worse survival (HR 1.9, 95% CI 1.3-2.7, p = 0.0003). Patients with a household income below $80,000 had an increased hazard of death (HR 1.8, 95% CI 1.3-2.5, p = 0.0009) compared to those with higher income. For clinical factors, as expected, disease stage strongly predicted outcome: distant spread (HR 5.1, 95% CI 3.3-8.1, p < 0.0001) and regional spread (HR 1.8, 95% CI 1.1-2.9, p = 0.0172) conferred worse survival compared to localized disease. Treatment with surgery was strongly associated with better survival (HR 0.4, 95% CI 0.26-0.61). Receipt of chemotherapy was associated with poorer survival (HR 1.9, 95% CI 1.1-3.0, p = 0.0127), likely reflecting its use in more aggressive disease. Conclusions: Malignant pheochromocytoma often follows an indolent course with good overall survival, though prognosis declines sharply with distant metastasis. This analysis identifies age and lower socioeconomic status as significant demographic predictors of worse mortality, suggesting healthcare disparities. Surgery remains the cornerstone of effective management. The association of chemotherapy with poorer survival likely indicates its application in advanced, high-risk cases rather than a negative treatment effect, highlighting the need for effective systemic therapies.