PTC, similar to HT, occurs more frequently in women, in connection with exposure to ionizing radiation and in areas with sufficient iodine intake [18]. 0.001). Using multiple logistic regression, positive anti-TPO was identified as an independent risk factor (OR 2.21, = 0.018), while spontaneously suppressed TSH 0.5?mIU/l was a protective factor (OR 0.3, = 0.01) against TC. In conclusion, nodules in subjects with positive antithyroid antibodies could be considered to have a higher risk of malignancy. However, based on our results, it is not possible to declare that TC is triggered by HT. 1. Introduction Thyroid cancer (TC) is the most common endocrine malignancy. Although it is still a rare disease, its incidence is growing rapidly in the last years, with approximately 14.3 new cases per 100,000 per year [1]. The most frequent histomorphological type is papillary thyroid cancer (PTC), which represents 84% of thyroid malignancies [2]. Despite extensive research, TC pathogenesis remains largely unclear with the relationship between TC and Hashimoto thyroiditis (HT) being a frequently discussed issue. HT is one of the most common autoimmune diseases, with an estimated frequency of 5C10% and with females affected 5x more likely than males are [3]. HT is characterized by T-lymphocyte infiltration of the thyroid gland, destruction of thyroid APD597 (JNJ-38431055) follicles, and their replacement by fibrotic tissue. The presence of antithyroid autoantibodies [against thyroid peroxidase (anti-TPO) or against thyroglobulin (anti-Tg)] and the typical thyroid ultrasound morphology (nonhomogeneous and hypoechoic ultrasound pattern of thyroid tissue, with increased vascularization) are the diagnostic markers of HT. HT is the most common cause of hypothyroidism Mouse monoclonal to XBP1 in iodine-sufficient areas [4]. The link between chronic inflammation and development of malignant tumors has been already proven in a number of human tumors, e.g., colorectal cancer and inflammatory bowel disease, hepatocellular carcinoma and chronic B and C hepatitis, cervical cancer, and HPV infection [5]. The possible relationship between HT and differentiated thyroid cancer has been first described by Dailey et al. in 1955 who observed frequent inflammatory cell infiltration surrounding thyroid cancer in thyroid histological samples [6]. Since that time, many papers with inconsistent results have been published. Some authors consider preexisting HT or the presence of antithyroid antibodies as a risk factor for developing TC [7C11], whereas others do not [12, 13]. The aim of this study was to compare the prevalence of antithyroid antibodies, thyroid dysfunction, and thyroid texture and volume measured by ultrasound in patients with TC and benign nodules (controls) recruited from subjects undergoing fine needle aspiration biopsy (FNAB) of thyroid nodules in our outpatient departments. We also analyzed available data for thyroid cancer-specific mortality and recurrence of TC. 2. Methods 2.1. Patients We retrospectively analyzed the results of all patients who underwent FNAB of thyroid nodules from 2006 to 2014 in 3 different outpatient departments in Prague and the Central Bohemian Region of the Czech Republic with sufficient iodine supply. The analysis included a total of 2571 patients with 2955 FNABs. Most of the patients (72%) were followed up at the 3rd Medical Department-Department of Endocrinology and Metabolism First Faculty of Medicine, Charles University, in Prague. It was designed as a retrospective nonrandomized cross-sectional study. Among subjects recommended for thyroid surgery, we identified individuals with histologically verified primary TC and included them into our study. For each patient with TC, we randomly selected two benign age- and sex-matched individuals APD597 (JNJ-38431055) who formed APD597 (JNJ-38431055) the control group. To be included in the control group, the patient had to meet following criteria: (1) benign cytology (Bethesda II), (2) benign histology or no significant progression or suspicious character of the nodule during at least one year of ultrasound follow-up, (3) available thyroid ultrasound and thyroid biochemical parameters (thyroid-stimulating hormone (TSH), anti-TPO, and anti-Tg) before thyroid biopsy. Furthermore, we analyzed the medical history of enrolled subjects for levothyroxine therapy. We did not distinguish what the primary goal of levothyroxine therapy was (substitution of hypothyroidism or suppression therapy). 2.2. FNAB and Thyroid Ultrasound Thyroid ultrasounds and FNABs were performed by two endocrinologists with at least 10 years of experience with thyroid ultrasound and biopsy. The decision to perform a FNAB was based on current guidelines for thyroid nodule diagnosis, and the procedure was guided by ultrasound. The cytopathology results were classified using the Bethesda reporting system [14]. The samples obtained prior to the introduction of Bethesda classifications were reclassified for the purpose of this study. Hypoechoic and nonhomogeneous thyroid texture was considered a positive ultrasound finding of HT. The total thyroid volume was calculated as a sum of.