Endocrine Abstracts

Background: During the past decades, the prevalence of both obesity and differentiated thyroid carcinoma increased worldwide. The link between obesity and thyroid cancer is controversial. Some studies found a relationship between obesity and thyroid carcinoma (especially BRAF^V600E mutated) and between type 2 diabetes mellitus and thyroid cancer, while other did not.

Aim: To assess the relationship between papillary thyroid carcinoma and increased body mass index (BMI).

Methods: Retrospective study by analyzing the files of patients with thyroid nodules who underwent thyroid surgery within a tertiary endocrine center. 101 patients (aged 54.5±14 years) with thyroid nodules were included. TSH, FT4 were measured by chemiluminescence. Preoperatively, fine needle aspiration and cytology exam were performed in suspicious nodules, according to current guidelines. Bethesda classification was used for reporting the results. After thyroidectomy, according to histology exam, 51 patients had multinodular nontoxic (MNG) and 50 had papillary thyroid carcinoma (PTC).

Results: Globally, normal BMI (18.5-24.99 kg/m²) was found in 27% of patients, while 47%were overweight and 26% were obese. 43% of patients were residents in iodine-deficient regions without significant differences between patients with MNG and PTC. Cytology exam was performed in 57 patients: Bethesda II was described in 11 patients (19,3%), Bethesda IV in 23 (40,35%), Bethesda V in 13 (22,8%), Bethesda VI in 7(12,28%) and for two patients our results came back inconclusive (Bethesda I – 3,5%) and 1 more patient (1,75%) had cytology exam performed from ganglia which came back positive for malignancy. Age was similar in patients with MNG (55.6±12.3 years) and in patients with PTC (55±15.6 years, P= ns). Mean TSH levels were similar in patients with MNG (1.2±0,81 mIU/l) and in patients with PTC (1.4±0,78 mIU/l, P= ns). Mean diameter of the largest nodule was significantly higher in patients with multinodular goiter (31.3±12.6 mm) than in patients with PTC (26.3±12 mm, P=0.02). Patients with normal BMI had similar mean diameter of the largest nodule (29.9±15 mm) with overweight and obese patients (31.63±11.2 mm, P= ns, t-test) and also showed a similar prevalence of PTC- 48.2% as compared with 48.6% in overweight and obese patients (P= ns, chi square). Mean TSH levels was slightly higher (1.49±0,80 mIU/l) in overweight and obese patients with PTC, than in patients with normal BMI (TSH= 1.26±0,75 mIU/l, P=ns).

Conclusion: In our retrospective series, there was no link between BMI and papillary thyroid cancer. Larger prospective studies are needed in order to clarify this relationship.