Influence of Body Mass Index on the Clinicopathological Features of Papillary Thyroid Carcinoma in a Chinese Population

<b><i>Background:</i></b> Previous studies suggested a relationship between obesity and a high risk of thyroid cancer. However, the association between high body mass index (BMI) and the aggressiveness of papillary thyroid carcinoma (PTC) is controversial. In this study, we aimed to investigate the impact of excess BMI on histopathologic aggressiveness of PTC in a Chinese population. <b><i>Methods:</i></b> Between January 2015 and September 2020, 4369 PTC patients who were tested for <i>BRAF</i> mutation at Jiangyuan Hospital were enrolled. Logistic regression analyses were used to evaluate the associations between BMI and clinicopathological features of PTC as well as tumor <i>BRAF</i> mutational status. <b><i>Results:</i></b> Of 4369 PTC patients, the mean BMI was 24.06 ± 3.49 kg/m², and <i>BRAF</i>^V600E mutations were detected in 3528 (80.8%) patients. BMI ≥24.0 at initial surgery was associated with tumor multifocality and bilaterality, but not with advanced tumor stage, extrathyroidal extension (ETE), ratio of positive lymph nodes >0.3, distant metastasis, or <i>BRAF</i>^V600E mutation. <b><i>Conclusion:</i></b> Our present study suggested that compared to patients with a normal BMI, overweight and obese patients had a greater risk of multifocality and bilaterality of PTC. No significant associations were observed between higher BMI and the more advanced tumor-node-metastasis stage or <i>BRAF</i>^V600E mutational status.