All-Cause Mortality and Secondary Malignancy in Patients with Pheochromocytoma/Paraganglioma

Background: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that can be fatal if not diagnosed early or adequately managed. This study investigated the risk of all-cause mortality and secondary malignancies in patients with PPGL compared to age- and sex-matched controls without PPGL. Methods: This nationwide population-based cohort study included 1,672 patients with PPGL and 16,790 controls with a median follow-up of approximately 7.1 years. A Cox proportional hazard model was used to estimate the adjusted hazard ratio (HR) and 95% confidence intervals (CI). Results: The mean age was 46.5 years and 50.5% were male. All-cause mortality was identified in 118 patients with PPGL (7.06%) and 749 controls (4.46%) during the follow-up period. The incidence of all-cause mortality in patients with PPGL was significantly higher than that in controls (9.92 per 1,000 person-years vs. 6.49 per 1,000 person-years, P=0.0003). The risk of all-cause mortality was significantly higher in patients with PPGL than in the controls (HR, 1.372; 95% CI, 1.124 to 1.675). The risk of secondary malignancies was significantly higher in patients with PPGL than in controls (HR, 1.612; 95% CI, 1.33 to 1.954) after adjusting. Among the various cancer subtypes, thyroid and prostate cancers were observed more frequently in PPGL patients, and these findings should be interpreted as descriptive trends. Conclusion: Patients with PPGL exhibited significantly increased risks of all-cause mortality and secondary malignancies compared with controls, highlighting the importance of appropriate assessment and follow-up.