EXPLORING THE LINK BETWEEN BMI AND AGGRESSIVE HISTOPATHOLOGICAL SUBTYPES IN DIFFERENTIATED THYROID CARCINOMA - INSIGHTS FROM A EUROPEAN MULTICENTRE RETROSPECTIVE STUDY

AUTHORS:
G. Di Filippo (Verona, Italy) , G. Lazzari (Verona, Italy) , E. Morelli (Verona, Italy) , D. Serbusca (Verona, Italy) , F. Medas (Monserrato, Italy) , G.L. Canu (Monserrato, Italy) , F. Cappellacci (Monserrato, Italy) , L. Rossi (Pisa, Italy) , B. Gjeloshi (Pisa, Italy) , M. Caradonna (Pisa, Italy) , I. Pliakos (Thessaloniki, Greece) , E. Poulios (Thessaloniki, Greece) , G. Kotsovolis (Thessaloniki, Greece) , T. Papavramidis (Thessaloniki, Greece) , P.G. Calò (Monserrato, Italy) , G. Materazzi (Pisa, Italy) , P. Brazzarola (Verona, Italy)
Background:
Obesity is a recognized risk factor for thyroid carcinoma but its role in the development of aggressive histopathological subtypes (AHS) is still unclear. We aimed to identify potential associations between Body Mass Index (BMI) and AHS of differentiated thyroid carcinoma (DTC).
Methods:
We conducted a multicentre retrospective study on patients who underwent thyroidectomy for DTC between January 2020 and December 2022 at 4 European tertiary referral centres for endocrine surgery. Based on BMI, patients were classified as normal-underweight (<25 Kg/m2), overweight (25-29.9 Kg/m2) or obese (>29.9 Kg/m2). AHS were defined according to 2022 WHO guidelines.
Results:
Among 3868 patients included in the analysis, 34.5% were overweight and 19.6% obese. Histopathological diagnoses were: 93.6% papillary (PTC), 4.8% follicular (FTC) and 1.6% Hürthle cell (HCC) thyroid carcinoma. Obese and overweight patients with PTC had a higher rate of AHS (p=0.030), bilateral, multifocal tumours (p=0.014, 0.049), and larger nodal metastases (p=0.017). At multivariate analysis BMI was found to be an independent predictor of AHS of PTC, irrespective of gender (B=0.018, p=0.028). In younger patients (<55 years old) with PTC >1 cm, BMI predicted higher ATA risk class (B=0.02, p=0.036). Overweight and obese patients with FTC had larger tumours (p=0.036). No difference was found in terms of aggressive subtypes of FTC and HCC based on BMI category.
Conclusions:
Overweight and obese patients with PTC are at increased risk for aggressive histopathological subtypes and clinico-pathological characteristics.