Endocrine Abstracts

Aim: Thyroid cancer comprises the most common endocrine malignancy and a variety of studies have investigated the role of thyroid autoimmunity as an independent risk factor for the manifestation of differentiated thyroid cancer in otherwise benign thyroid disorders. Objective of the current retrospective study is the assessment of any possible correlation between thyroid autoimmunity, in terms of elevated thyroid autoantibodies, and incidental thyroid microcarcinoma (ITC) in non-toxic nodular thyroid diseases, subjected to total thyroidectomy (TT).

Patients and methods: In First Surgical Department between 1 January 2005 and 01 March 2010 a total of 186 patients (146 females/40 males) underwent TT after referral for benign non-toxic nodular thyroid diseases. Surgical specimens were evaluated in University Pathology Department and the diagnosis of ITC was recorded. Elevated thyroid autoantibody titers were assessed in patients without (group A) and those with (group B) thyroid cancer. The results were also compared regarding preoperative diagnosis.

Results: 32 patients (17.2%) were diagnosed with microcarcinoma (females/males: 2.2/1), while 154 patients (82.8%) were free of malignancy. 9/34 patients with solitary thyroid nodule (STN) and 33/152 subjects with multinodular goiter (MNG) had biochemical signs of thyroid autoimmunity. 9/32 (28.1%) cancer patients had elevated thyroid autoantibodies preoperatively. The prevalence of thyroid autoimmunity was higher (non-statistically significant) in the cancer-group compared to the non-cancer cohort (28.1% vs 21.4% respectively; P=0.41). Furthermore, the prevalence of thyroid microcarcinoma was also higher (non-statistically significant) in the autoimmunity subgroup compared to the non-autoimmunity subgroup (21.4% vs 16%; P=0.41). These differences were manifested solely in the MNG group.

Conclusions: Thyroid autoimmunity does not seem to feature an independent risk factor associated with thyroid microcarcinoma in non-toxic nodular thyroid diseases. However, a non-significant higher correlation is recognized in the subgroup of euthyroid multinodular goiter. Further studies are required to investigate the potential association between thyroid autoimmunity and carcinoma, as a helpful indication for surgical referral.