Abstract: Saliva Proteomic Diagnostic Model for Thyroid CancerKehuan SUN1, ZhengzhiWU2,3, Meiqun CAO3Corresponding author: ZhengzhiWU, E-mail: szwzz001@163.com1Southern Medical University, Guangzhou 510515, China2Institute of Integrated Chinese andWestern Medicine, The First Affiliated Hospital to Shenzhen University, Shenzhen 518035, China3Shenzhen Institute of Gerontology, The Second Clinical Medical College to Ji'nan University, Shenzhen 518020, ChinaThis work was supported by the National Natural Science Foundation of China ( No. 30640071 ) and the Science and Technology Plan-ning Project of Guangdong Province ( No. 2010B030700005 )Abstract Objective: To explore the specific biomarkers in saliva of thyroid cancer patients using Surface enhanced laser desorp-tion ionization time of flight mass spectrometry ( SELDI-TOF-MS ) technique and to establish diagnostic model. Methods: The salivaprotein fingerprints of 45 thyroid cancer cases and 43 healthy controls were detected with SELDI-TOF-MS, then the specifically ex-pressed proteins in the saliva of thyroid cancer patients were used to establish the diagnostic model through bioinformatic methods. Re-sults: The saliva protein fingerprint data of the two groups were compared and 28 discrepant protein peaks were found ( P < 0.01 ). The4 peaks of M/Z3491.10, 3642.28, 4315.10 and 7424.63 were used to build the best decision tree model. The accuracy, sensitivity andspecificity of the diagnostic model were 81.8 % ( 72/88 ), 88.9 % ( 40/45 ) and 74.4 % ( 32/43 ), respectively. Conclusion: Diagnosticmodel with specifically expressed proteins in the saliva of thyroid cancer patients has high sensitivity and specificity for preoperative di-agnosis of thyroid cancer and is worthy of further exploration and application.Keywords Thyroid cancer; Saliva; Proteomics; Diagnostic model;Surface enhanced laser desorption ionization time of flight mass spectrometry