基于血清肽组学的甲状腺癌术后风险实时评估标志物研究

Serum thyroglobulin measurement has been occurred owing to its role as a marker in detecting the presence or residual, recurrence or metastases in patients with differentiated thyroid cancer (DTC) after total or near-total thyroidectomy. In many cases, these immunoassays could be affected by anti-Tg autoantibodies result in falsely measurements. Therefore, there has been an urgent need in an individualized approach for DTC patients, centered in tumor biomarkers for risk stratification especially after total thyroidectomy or lobectomy. Previously, we developed a novel matrix-assisted laser desorption/ionization time-of flight-mass spectrometry based method for serum peptidome signature identification. We found serum kinins levels were correlated with the pre- and postoperative tumor burden in DTC patients. In this proposal, we will optimize and validate this method and propose to use the information provided by biofunctional peptides circulating in the bloodstream for an individualized approach as well as long-term risk stratification for DTC patients after total thyroidectomy.

血清甲状腺球蛋白水平是目前评价甲状腺癌术后肿瘤残留及监测病情变化的重要指标，但由于血清甲状腺球蛋白抗体的存在会干扰检测结果导致假阳性或假阴性，造成对术后病人错误的临床风险分级，从而导致过度治疗或治疗不足。因此，寻找甲状腺癌术后实时的肿瘤残留监测、复发及转移风险评估标志物具有重大意义。我们在前期研究中建立了血清小分子多肽的基质辅助激光解吸电离飞行时间质谱快速检测方法，并发现血清中的小分子缓激肽水平与甲状腺癌病人术前、术后肿瘤负荷正相关，有望成为甲状腺癌术后监测和风险评估的有效标志物。本研究拟在此基础上优化缓激肽的检测方法，并进行不同人群的临床大样本验证，研究该标志物的特异性和灵敏度，及其在术后长期随访中的预警作用。可望为发展甲状腺癌病人术后病况实时监测、精准诊断和治疗奠定基础，并为长期随访提供新的手段。

由于血清甲状腺球蛋白检测的局限性，目前缺少高灵敏性和特异性的血清标志物用于对甲状腺小结节的良恶性诊断、甲状腺乳头状癌分级和术后监测。本项目通过质谱技术建立血清甲状腺乳头状癌蛋白质图谱，发现血清缓激肽、LDHA、Lipocalin-2可以较好区分甲状腺良性结节和甲状腺乳头状癌。独立队列验证血清缓激肽检测灵敏度和特异性为72.4%和91.8%，AUC=0.895(0.841-0.949)。血清LDHA检测灵敏度和特异性为95.08%和78.69%，AUC=0.910(0.856-0.964)。血清Lipocalin-2检测灵敏度85.25%、特异性72.22%，AUC=0.812(0.72-0.904)。另外在独立队列验证时我们发现血清缓激肽不能提示术后疗效，而LDHA、Lipocalin-2可以较好区分甲状腺乳头状癌和肿瘤切除术后疗效。独立队列验证血清LDHA检测灵敏度78.69%、特异性81.97%，AUC=0.863(0.796-0.923)。血清Lipocalin-2检测灵敏度70.49%、特异性44.26%, AUC=0.573(0.47-0.675)。因此，我们提出联合血清LDHA、Lipocalin-2检测可以作为鉴别甲状腺乳头状癌以及评价术后疗效的潜在标志物。联合血清LDHA、Lipocalin-2检测区分甲状腺乳头状癌和甲状腺良性结节的检测灵敏度91.8%、特异性80.56%，AUC=0.908(0.847-0.97)。区分甲状腺乳头状癌和肿瘤切除术后效果的检测灵敏度85.25%、特异性77.05% ，AUC=0.573(0.80-0.931)。我们的发现为研究甲状腺乳头状癌的生物学行为提供了理论基础，并且为下一步大型临床队列验证可能用于辅助鉴别诊断甲状腺乳头状癌和可能预测甲状腺癌患者术后疗效的标志物奠定工作基础。