Preoperative Factors Associated with Extrathyroidal Extension in Papillary Thyroid Cancer

Objective:Extrathyroidal extension may not be accurately recognized during thyroidectomy and can increase the risk of positive margins and even recurrence. This study aimed to investigate the preoperative factors associated with extrathyroidal extension.Methods:We analyzed 887 patients with papillary thyroid cancer (PTC) who underwent surgery in the period of 2005-2017. Binary logistic regression analyses and generalized additive models were used to identify associations.Results:Minimal extrathyroidal extension was present in 233 (26%) patients and advanced extrathyroidal extension was found in 60 (7%) patients. Age, BMI, and tumor size were independent predictors of all or advanced extrathyroidal extension. Among the 493 patients whose BRAF mutation status was available, age (OR = 1.025), BMI (OR = 1.091), tumor size (OR = 1.544), andBRAFV600E mutation (OR = 2.311) were independently associated with extrathyroidal extension.Conclusions:Older age, a greater BMI, a larger tumor size, and presence of theBRAFmutation were predictive of extrathyroidal extension. These factors should be taken into consideration in decision-making before surgery is performed.