Non-Functional Carotid Body Tumors in Patients Without Somatic Mutations May Be Considered for Non-Operative Management

Abstract

Carotid Body Tumors (CBT) are rare neuroendocrine paragangliomas which are typically asymptomatic and benign, with a low rate of biochemical functionality. Historically, early surgical excision was recommended to prevent development of CBT-related complications. Yet, CBT resection can result in significant cranial nerve and vascular injuries. Recent work has shown successful primary observation without resection of non-carotid body, cranial paragangliomas with slow growth and low rate of neuropathies. We hypothesize that primary observation of CBT is safe and may be considered for majority of CBT. Retrospective cohort study of patients at a multi-hospital healthcare system with radiologic identification and/or diagnostic or procedural billing codes for CBT (2000-2019). Tumor size (greatest diameter), associated symptoms, and interventions were recorded at the initial evaluation and throughout follow-up. Multivariable logistic regression investigated the risk of initial surgical resection. A total of 108 patients (mean age, 59±19years; 67% female), with 123 CBT (mean diameter 23±12mm; 52% right) were initially evaluated by otolaryngologists (51%), vascular surgeons (25%), neurosurgeons (8%), or other (16%) medical providers. Fity-five CBT were initially resected, 63 observed, and 5 irradiated. Initial resection was associated with younger age (adjusted odd ratios aOR, 0.95 [95% confidence intervals CI, 0.92-0.97]), male sex (aOR, 4.82 [95% CI, 1.47-15.75]), and evaluation by a vascular surgeon (aOR, 6.17 [95% CI, 2.04-18.63]). Overall median follow-up was 4.7 (IQR, 2.6-9.1) years. Initially observed CBT were on an average stable in size (mean 1 ± 5mm/year), none became biochemically active, and 2 patients became symptomatic. At the final follow-up, 63 (51%) underwent surgical resection, 54 (44%) observation, and 6 (5%) radiation therapy. Of the 63 surgically resected CBT, 5 (8%) patients had malignant CBT of which 3 (60%) had known somatic mutations (polymerase epsilon [n=1], succinate dehydrogenase-D gene [n=2]). Thirty percent of CBT resections had in-hospital postoperative complications, notably including 1 stroke which occurred in an initially observed patient and 16 cranial nerve complications which all occurred in immediately resected patients. Three resected CBT locally recurred, only 1 of which had malignant pathology. Patients with newly diagnosed CBT require biochemical functionality and somatic mutation testing. In the absence of these findings, initial observation of CBTs with annual imaging and symptom monitoring may be considered an alternative to immediate resection which demonstrates a high risk of clinically meaningful postoperative complications.