Clinicopathological Features, Tumor Localization and Treatment Outcomes in Paraganglioma: A Single-Center Medical...

Background/Objectives: Paragangliomas (PGLs) are rare neuroendocrine tumors, and data describing them from a medical oncology perspective are limited. We characterized clinicopathological features, tumor localization, and treatment outcomes. Methods: We retrospectively analyzed 43 patients with PGL at a single medical oncology department. The primary endpoint was recurrence-free survival (RFS), defined as time to first recurrence or death from any cause; overall survival (OS), objective response rate (ORR), disease control rate (DCR), and prognostic associations were secondary. Results: Median age was 44 years, 60.5% were female, and tumors were sympathetic (extra-adrenal) in 55.8% and parasympathetic (head and neck) in 39.5%. After a median follow-up of 116.8 months, 40 patients (93.0%) underwent resection, among whom 14 RFS events occurred (13 recurrences, 1 unrelated death). Median RFS and OS were not reached (60-month RFS, 67.1%; 120-month OS, 83.3%). Among nine patients receiving first-line systemic therapy (eight response-evaluable), ORR was 12.5% and DCR 37.5%. In exploratory univariable analysis, a Ki-67 index ≥ 3% correlated with recurrence (time-averaged hazard ratio, 4.53; 95% CI, 1.55-13.19; p = 0.006), alongside an R1 resection margin (not significant after Bonferroni correction). Conclusions: These findings may support further evaluation of Ki-67 within risk-adapted surveillance but do not replace germline testing.