Published by Bioscientifica Ltd. Printed in Great Britain © 2020 European Society of Endocrinology https://eje.bioscientifca.com https://doi.org/10.1530/EJE-20-0350 European Journal of Endocrinology 183:3 317–323 M Rotondi and others Autoimmune thyroiditis and thyroid cancer Patients with chronic autoimmune thyroiditis are not at higher risk for developing clinically overt thyroid cancer: a 10-year follow-up study Mario Rotondi 1,2 , Gloria Groppelli 3 , Laura Croce 1,2,4 , Francesco Latrofa 5 , Giuseppe Ancona 2 , Francesca Coperchini 1 , Daniela Pasquali 6 , Carlo Cappelli 7 , Alessandro Fugazza 8 , Valeria Guazzoni 3 , Giorgio Radetti 9 and Luca Chiovato 1,2 1 Istituti Clinici Scientifci Maugeri IRCCS, Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, Pavia, Italy, 2 Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy, 3 Unit of Internal Medicine, Medical-Oncologic Department, ASST Lodi, Lodi, Italy, 4 PhD course in Experimental Medicine, University of Pavia, Pavia, Italy, 5 Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy, 6 Department Advanced Medical and Surgical Science, A.O.U. Vanvitelli, University of Campania ‘Luigi Vanvitelli’, Naples, Italy, 7 Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy, 8 Digestive Endoscopy Unit, Department of Gastroenterology, Humanitas Research Hospital, Rozzano, Italy, and 9 Marienklinik, Bolzano, Italy Abstract Objective: The association between chronic autoimmune thyroiditis (CAT) and diferentiated thyroid cancer (DTC) remains controversial. The incidence of DTC increases when screening procedures are implemented, as typically occurs in CAT patients being routinely submitted to thyroid ultrasound (US). The aim of this study was to longitudinally evaluate the long-term development of DTC in patients with CAT. Design and methods: A retrospective longitudinal cohort study was designed. For the study, 510 patients with chronic autoimmune thyroiditis (CAT) with a 10-year follow-up were enrolled. Patients were divided in two groups according to the presence (CAT+ NOD+; n = 115) or absence (CAT+ NOD−; n = 395) of co-existent nodules at diagnosis. The main outcome measures were appearance of new thyroid-nodules and development of DTC during follow-up. Results: During a 10-year median follow-up period, new thyroid-nodules were detected in 34/115 (29.5%) patients in the CAT+ NOD+ group and in 41/395 (10.3%) in the CAT+ NOD− group (P < 0.001). Logistic regression analysis showed that thyroid-volume at diagnosis and belonging to the CAT+ NOD+ group signifcantly predicted the appearance of a new thyroid nodule during follow-up, independently of baseline age and sex. Among the 75 patients experiencing the appearance of a new nodule, 27 (39%) met the criteria for fne-needle-aspiration-cytology (FNAC). A benign cytological diagnosis was rendered in all cases. Conclusions: In our series of CAT patients, the appearance of new thyroid-nodules was frequent, but none of them were found to be malignant. The presence of CAT appears to be associated with a negligible risk of developing clinically overt DTC. Correspondence should be addressed to L Chiovato Email luca.chiovato@icsmaugeri.it European Journal of Endocrinology (2020) 183, 317–323 Clinical Study Downloaded from Bioscientifica.com at 11/05/2021 12:35:49AM via free access