Open AccessInvestigating the Effect of Thyroid Nodule Location on the Risk of Thyroid Cancer
Author(s) -
Sina Jasim,
Thomas J. Baranski,
Sharlene A. Teefey,
William D. Middleton
Publication year - 2020
Publication title -
thyroid
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.918
H-Index - 142
eISSN - 1557-9077
pISSN - 1050-7256
DOI - 10.1089/thy.2019.0478
Subject(s) - medicine , thyroid nodules , nodule (geology) , thyroid cancer , thyroid , odds ratio , confidence interval , malignancy , radiology , paleontology , biology
Background: Thyroid nodules are routinely evaluated with ultrasound. Our aim was to determine if thyroid nodule location was a useful feature to predict thyroid cancer. Materials and Methods: Retrospective review of patients with thyroid nodules from six referral centers from 2006 to 2010. A total of 3313 adult patients with thyroid nodules and confirmed benign or malignant thyroid diagnoses were included. Results: Mean patient age was 54.2 (18-97) years, and the majority were women ( n = 2635, 79.8%). A total of 3241 nodules were analyzed, 335 (10.3%) of which were malignant. Thyroid nodule location was an independent risk factor in predicting thyroid cancer ( p = 0.005). Thyroid cancer odds were highest in the isthmus (odds ratio [OR] = 2.4, 95% confidence interval [CI] 1.6-3.6, p < 0.0001). In a multivariate regression model adjusting for age, sex, family history of thyroid cancer, radiation exposure, nodule size, and American College of Radiology (ACR) TI-RADS (Thyroid Imaging Reporting and Data System) score, the isthmus nodules had the highest risk of malignancy (OR = 2.4 [CI 1.5-3.9], p = 0.0007), followed by upper thyroid nodules (OR = 1.8 [CI 1.2-2.7], p = 0.005) and then middle thyroid nodules (OR = 1.5 [CI 1.1-2.0], p = 0.01) compared with lower thyroid nodules. Isthmus nodules were significantly smaller in size compared with middle ( p < 0.0001) and lower ( p = 0.0004), but not upper nodules ( p = 0.25), with a mean size of 15.5 mm (±10.7). Conclusions: Thyroid nodule location is an independent risk factor in predicting the risk of thyroid cancer. Isthmic nodules carry the highest risk of cancer diagnosis and lower lobe nodules carry the lowest risk.