Serum level of interleukin-17 and interleukin-35 as a biomarker for diagnosis of thyroid cancer.

Objective: The aim of this study was to evaluate the serum level of interleukin-17 (IL-17) and IL-35 in thyroid cancer patients and its diagnostic value as a biomarker. Methods: Sixty-one thyroid carcinoma patients were recruited from January 2012 to December 2014 in our hospital. Of the 61 included cases, 42 subjects were pathology confirmed with thyroid cancer and other 19 cases were diagnosed with thyroid adenoma. The serum level of IL-17 and IL-35 were compared between the two groups. The diagnosed sensitivity, specificity, and receiver operating characteristic curve (ROC) for serum IL-17 and IL-35 were evaluated according to Bayes theorem. Results: The serum level of IL-17 were 16.3 +/- 4.1 pg/ml and 9.4 +/- 3.6 pg/ml for the thyroid cancer and thyroid adenoma patients respectively, with statistical difference (P < 0.05). The serum level of IL-35 were 48.8 +/- 7.8 pg/ml and 62.3 +/- 9.6 pg/ml for the thyroid cancer and thyroid adenoma patients, respectively, which indicated that the thyroid adenoma group was much higher with statistical difference (P < 0.05). The diagnosis sensitivity and specificity for serum IL-17 were 71.4% and 80.2% at the cutoff value of 12.1 pg/ml with the area under the ROC of 0.8239. The diagnosis sensitivity and specificity for serum IL-35 were 76.8% and 82.4% at the cutoff value of 57.6 pg/ml with the area under the ROC of 0.8722. Conclusion: The serum level of IL-17 and IL-35 was significantly different between thyroid cancer and thyroid adenoma patients, which could be a potential biomarker for the diagnosis of malignant thyroid tumor.