Serum Treg/Th17-Related Cytokines and Systemic Inflammatory Indices in Differentiated Thyroid Cancer

This study measures circulating immune-signaling molecules before thyroid surgery to determine whether they differ between patients whose thyroid nodule proves to be a differentiated thyroid carcinoma and patients whose nodule proves to be benign. Adults scheduled for elective thyroidectomy for a thyroid nodule or nodular goiter are enrolled consecutively before surgery, while the nature of the nodule is still unknown. One additional blood tube is obtained during the routine preoperative blood sampling that is performed for every patient on the day of hospital admission, one day before surgery. No separate venipuncture, no additional test, no additional visit and no change to diagnosis, treatment or follow-up is involved. Serum interleukin-17A, measured before surgery, is the primary outcome measure. Additional Treg/Th17-related cytokines, the interleukin-17A to interleukin-10 ratio, and systemic inflammatory indices calculated from the same blood draw are secondary outcome measures. Participants are assigned to the differentiated thyroid cancer group or the benign nodular goiter group after surgery, on the basis of the final histopathology report.

Inclusion Criteria: * Age 18 to 75 years * Scheduled for elective thyroidectomy for a thyroid nodule or nodular goiter * Euthyroid, defined as thyroid stimulating hormone and free thyroxine within the laboratory reference range on the day of blood sampling * Written informed consent * Final histopathology of differentiated thyroid carcinoma of papillary, follicular or oncocytic type (case group), or of benign nodular goiter (control group) Exclusion Criteria: * Graves disease, toxic multinodular goiter, toxic adenoma, or hyperthyroidism of any cause * Active infection * Any active non-thyroid malignancy * Systemic autoimmune or inflammatory disease other than Hashimoto thyroiditis * Use of immunosuppressive or systemic corticosteroid therapy * Pregnancy