Primary Tumour Resection For Synchronously Metastatic Phaeochromocytoma And Paraganglioma: A Population-Based Study

Context Until recently, there are few effective treatment options for patients with synchronous metastatic phaeochromocytoma (PHEO) and paraganglioma (PGL). Surgical resection may improve the survival outcomes of these patients.Objective To assess the role of surgical resection of the primary tumour in patients with synchronous metastatic PHEO and PGL.Design Retrospective analysis of patients with synchronous metastatic PHEO/PGL using the Surveillance, Epidemiology, and End Results database (1988-2016).Patients Patients with synchronous metastatic PHEO/PGL who underwent primary tumour resection.Measurements Overall survival and Cox regression analyses.Results A total of 99 patients with metastatic PHEO and 127 metastatic PGL patients were identified from the SEER database. Compared to metastatic PHEO, metastatic PGL patients had a better overall survival (5-year survival rate: 33.3% vs. 49.0%, p = .001). In metastatic PHEO patients, 53 (53.5%) patients underwent surgery for primary site. Surgically treated patients had an improved survival compared to non-surgery patients (5-year survival rate: 50.9% vs. 29.6%, p = .017). Among metastatic PGL patients, primary tumour resection was performed in 74 (58.3%) patients and had no significant effect on the survival of metastatic PGL. In sub-analyses, surgery only conferred a survival benefit in patients with primary tumours originated from aortic/carotid bodies, rather than other sites or abdominal tumours.Conclusion Our findings suggest that primary tumour resection is associated with improved survival in patients with synchronous metastatic PHEO and those with PGL diseases located in aortic/carotid bodies. In addition, PHEO and PGL should be treated as two distinct clinical entities.