Epidemiology, characteristics, management, and survival of patients with malignant carotid body tumors: A systematic review and meta-analysis of current evidence.

Background and AimMalignant carotid body tumors (CBTs) represent a rare clinical entity, with existing studies limited by small sample sizes and fragmented data. This systematic review aims to: (1) Pool epidemiological estimates of malignant CBTs; (2) Characterize clinicopathological profiles; (3) Evaluate treatment modalities and survival outcomes; (4) Identify risk factors for malignant transformation.MethodsA comprehensive search of PubMed, Scopus, Cochrane Library, and Web of Science was conducted through January 1, 2024 for literatures with malignant CBTs. The incidence, clinicopathological features, management and survival of patients with malignant CBTs were pooled analyzed and described. Benign and malignant CBTs were compared to identify any relevant risk factors of malignant transformation for CBTs. Two independent reviewers performed study selection, data extraction, and quality assessment. All statistical analyses were performed using the standard statistical procedures provided in Review Manager 5.2 and Stata 12.0.ResultsA total of 99 reports and 447 patients with malignant CBTs were identified. The pooled results indicated that the incidence of malignant CBTs was 5% (4% ‒ 6%) with a mean age of 44.11 years. In addition, female patients with malignant CBTs accounted for 61% and 14.58% experienced bilateral lesions. 74.63% malignant CBTs were defined as Shamblin III with a mean maximal diameter of 5.19 cm. We found that compared to patients with benign CBTs, patients with malignant CBTs experienced significantly higher proportion of Shamblin III (OR 4.65; 95% CI 1.80-12.06) and preoperative symptoms (hoarseness/dysphonia) (OR 7.96; 95% CI 1.79-35.5) respectively. It was observed that patients with malignant CBTs experienced more vascular and neurologic complications including vascular reconstruction or repair (OR 19.22; 95% CI 6.23-59.3), overall neurological complication (OR 3.81; 95% CI 1.28-11.36) and permanent nerve deficits (OR 3.95; 95% CI 1.26-12.41) respectively.ConclusionsThis meta-analysis established that malignant CBTs were more likely to be Shamblin III with larger size and common in middle-aged female. The majority of patients with malignant CBTs experienced preoperative systems. Preoperative hoarseness/dysphonia was associated with malignancy. Malignant CBTs increased vascular and neurologic complications. Postoperative radiotherapy was mainly used for malignant CBTs. Cohort studies with enough sample size and long follow-up are required to clear the risk factors, treatment and survival of malignant CBTs.