Outcomes and Therapeutic Strategies for Head-and-neck Paragangliomas Associated With Succinate Dehydrogenase Mutations

Abstract

Context: Natural history and optimal therapeutic strategies of patients with head-and-neck paragangliomas (HNPGL) associated with germline mutations in succinate dehydrogenase genes (SDHx) are barely known. This study aims to describe the outcome of these patients depending on selected strategies.

Methods: We retrospectively analyzed the outcome of 65 SDHx-mutated patients presenting 108 HNPGL mostly located in the carotid (57%) and jugulotympanic (JT) (21.5%) areas. One hundred five HNPGLs (97%) were nonsecreting and nonmetastatic, with multiple tumors observed in 40 patients (62%). HNPGLs were initially managed by surgery for 56 (52%), monitoring for 31 (29%), and radiotherapy for 21 (19%). Unsuccessful tumor control (UTC) was defined as a tumor volume increase or a need to change therapeutic strategy. During a 7-year median follow-up period, 18 UTCs (17%) were observed in 17 patients. Among operated HNPGLs, 13 (23%) had an UTC, compared with 1 (5%) among the irradiated HNPGL and 4 (13%) among monitored HNPGLs. The incidence of UTC was significantly increased in HNPGL treated by incomplete surgical resection compared to HNPGL treated by complete surgery (50% vs 0%, P < .001). UTC was more frequent in the JT than in other locations (39% vs 11%, P < .002).

Results: Posttherapeutic complications were observed in 34 patients (55%), mainly neurological (73%) or vascular (15%), with a higher incidence after surgery than after irradiation (66% vs 14%, P < .001).

Conclusions: Most SDHx patients with monitored HNPGLs had a stable disease confirming the interest of initial time for observation before deciding to treat or not, particularly in asymptomatic patients.

Keywords: monitoring; paraganglioma; radiotherapy; succinate dehydrogenase; surgery; tumoral progression.