Comparison of Oncocytic and Follicular Carcinoma of the Thyroid Without Initial Distant Metastasis

Oncocytic thyroid carcinoma (OTC) is recognized as a distinct entity of follicular thyroid carcinoma (FTC), and its prognosis has traditionally been considered poor. However, the available data on this topic remain limited and highly heterogeneous. The objective of this study was to investigate the clinicopathological features and prognosis of patients with OTC and compare them with those of patients with FTC.

A retrospective comparative study of all patients who underwent total thyroidectomy for OTC or FTC in a high-volume endocrine surgery center between January 2005 and December 2021. Demographic and clinicopathological characteristics, complications, and recurrence rates were compared using univariate and multivariate regression analyses.

In total, 347 patients, 72% female, median age 48 years (35-61 years) were enrolled, including 123 with OTC and 224 with FTC. Patients were significantly older in the OTC group than in the FTC group (54.7 vs. 44.5 years, respectively, p = 0.001). With respect to other demographic, clinical, and pathological characteristics, no statistically significant differences were observed between the two groups. The median follow-up duration was 5.6 years (3.2-10.5 years). Eighteen patients (5.2%) experienced recurrence, including 7 (5.7%) in the OTC group and 11 (4.9%) in the FTC group. No difference in recurrence-free survival was observed between the OTC and FTC groups (p = 0.47). In multivariate analysis, histological type was not associated with the risk of recurrence.

Patients withOTC have the same recurrence rate as do patients with FTC . It does not appear justified to propose a different therapeutic management for this histological type, and a stepdown management could be proposed.