Exploring the Interplay of TGF-β and Body Weight in Thyroid Cancer: A Comparative Analysis of Cytokine Levels Before and After Surgery in Differentiated Thyroid Cancer and Obese Patients with Nodular Goiter

Introduction: Thyroid cancer and obesity are prevalent conditions with significant global health implications. Differentiated thyroid cancer (DTC) is influenced by various molecular pathways, including those involving Transforming Growth Factor-Beta (TGF-β), a cytokine implicated in cell proliferation, differentiation, immune regulation, and fibrosis. Obesity (BMI > 30) has been associated with thyroid dysfunction and an increased incidence of nodular goiter. However, the relationship between TGF-β levels, thyroid malignancies, and metabolic disturbances remains unclear. This study aimed to analyze TGF-β1, -2, and -3 concentrations in blood serum before and after thyroidectomy in patients with DTC and obese individuals with nodular goiter to evaluate their potential role in thyroid pathology and obesity-related metabolic changes. Methods: A prospective study was conducted at a high-volume surgical center where over 700 thyroidectomy procedures are performed annually. Seventy-six consecutive patients (aged 26–79 years) were included: 21 with DTC and 55 with euthyroid nodular goiter. The latter group was subdivided based on BMI into obese (BMI > 30, n = 26) and non-obese (BMI < 30, n = 29) cohorts. Blood samples were collected preoperatively and on the first postoperative day for TGF-β quantification using the Bio-Plex Pro™ Human Cytokine Assay. Statistical analysis was performed using the Student’s t-test. Results: Postoperatively, patients with DTC exhibited significantly higher TGF-β1 (210,000 pg/mL), TGF-β2 (360 pg/mL), and TGF-β3 (170 pg/mL) levels compared to obese patients with nodular goiter (p < 0.05). In the nodular goiter group, BMI did not significantly influence preoperative TGF-β levels (p > 0.05). However, postoperatively, obese patients showed lower TGF-β1 (100,000 pg/mL) and TGF-β2 (30 pg/mL) levels compared to normal-weight individuals (p = 0.03), while no significant difference was observed for TGF-β3 (p > 0.05). Conclusions: The study highlights distinct alterations in TGF-β isoform levels in thyroid cancer and obesity. Elevated postoperative TGF-β levels in DTC patients suggest a role in tumor progression and response to surgical intervention. In contrast, the reduction of TGF-β1 and TGF-β2 levels in obese patients postoperatively may indicate a complex interplay between obesity, surgical stress, and cytokine regulation. These findings underscore the need for further research into the molecular mechanisms governing TGF-β dynamics in thyroid disorders and obesity, with potential implications for therapeutic interventions.