Thyroid gland invasion in total laryngectomy: A systematic review and meta-analysis

Although guidelines indicate that thyroidectomy should be performed routinely during total laryngectomy in patients with advanced laryngeal cancer, its clinical indications remain controversial. Some researchers believe that thyroid invasion is uncommon and that thyroid preservation should be considered in most cases.This study aimed to identify the incidence and predictors of thyroid invasion in patients with laryngeal cancer to facilitate decision-making regarding whether to perform thyroidectomy during total laryngectomy.The author conducted a systematic review and meta-analysis of all published articles retrieved from a search of the MEDLINE (1982-2020) and EMBASE (1971-2020) databases. The published studies of advanced laryngeal cancer with total laryngectomy and partial or total thyroidectomy for laryngeal cancer were selected. The incidence and predictors of thyroid invasion were analyzed.We analyzed 25 studies (2177 cases), of which 176 people (8.08%) had thyroid invasion. Subglottic tumors (odds ratio [OR], 3.74; 95% CI, 1.75-7.99), T4 stage tumors (OR, 2.39; 95% CI, 1.20-4.75), subglottic extension (OR, 3.85; 95% CI,2.09-7.11), and thyroid cartilage invasion (OR, 3.98; 95% CI, 1.47-10.75) are risk factors for thyroid invasion, and no statistically significant difference was noted between recurrent tumor and thyroid invasion.The risk of thyroid invasion was significantly higher when advanced laryngeal cancer involved subglottic tumors, T4 stage tumors, subglottic extension, and thyroid cartilage invasion. The overall incidence of thyroid gland invasion was low; therefore, thyroidectomy may be performed for cases deemed risky rather than as a routine measure of total laryngectomy. RESEARCH REGISTRY UIN: reviewregistry1226.