Thyroid gland invasion in total laryngectomy and total laryngopharyngectomy: a systematic review and meta‐analysis of the English literature

Abstract

Advanced laryngeal and hypopharyngeal carcinomas involving the subglottis carry a significantly elevated risk of thyroid gland invasion compared with those that spare this subsite. The overall incidence of thyroid gland invasion is low, and therefore, thyroidectomy should be reserved for cases considered to be at risk as opposed to a being a routine measure for all total laryngectomies.

Management of the thyroid gland during laryngectomy

“…17,18 A systematic review and meta-analysis from Newcastle upon Tyne Hospitals highlighted that the relative risk of thyroid gland invasion for patients with subglottic extension was 4.3 (95 per cent CI = 2.5–7.2). 19 While our study confirms the significance of cartilage invasion, the positive predictive value remained low (less than 30 per cent), even for statistically significant associations. The low positive predictive value and high negative predictive value are attributed to the low natural prevalence of thyroid involvement in primary laryngeal squamous cell carcinoma.…”

Evidence and evidence gaps of laryngeal cancer surgery

“…Two meta-analyses from 2009 [185] and 2013 [186] analyzed risk factors for infiltration of the thyroid gland by squamous cell carcinomas of the larynx. A meta-analyses published by Mendelson et al [185] included 8 studies with 399 patients.…”

“…Surprisingly, the presence of cartilage infiltration by the tumor was no significant predictor for infiltration of the thyroid gland, however, the significance was limited by the fact that only 2 relatively small studies had performed such an analysis [185]. The meta-analysis performed by Kumar et al [186] included 16 studies. The incidence of infiltration of the thyroid gland amounted to 10.7% of a population of 1,287 patients.…”

“…The incidence of infiltration of the thyroid gland amounted to 10.7% of a population of 1,287 patients. Patients with primarily subglottic tumors and tumor spread into the subglottis had a clearly higher risk of thyroid infiltration [186]. …”

“…Probably, this is less frequently caused by infiltration of the thyroid gland itself but rather by the characteristics of the tumors infiltrating the thyroid gland: advanced transglottic tumors with infiltration of the subglottis and primarily subglottic tumors [185], [186]. Further studies are required to assess the actual influence of an infiltration of the thyroid gland on the survival.…”